This multi-fx stompbox tops my current hardware wishlist. Kinda pricey at $499, but it does pretty much everything you want in a general-purpose effect. What sold me, as a keyboard player: MIDI in/out and stereo inputs and outputs. The stereo "tape flutter" effect is quite nice, too.
 
Less-compelling but still very cool: the Blackhole reverb effect, reverse audio and "ultra-swell" (envelope follower).
 
Not compelling but might be more useful than I think: bluetooth connection to iOS/Android/computer app.
 
There is also a less-expensive ($399) model called H9 Core (use the app for online purchases of additional algorithms), as well as a high-end version call H9 Max for $699. Near as I can tell, the only difference between the 3 models is how many algorithms come with it.
 

I paid more that 2x that for my H3000 back in the day. More like 2x the H9 Max IIRC. Enjoyed the unit until the smoke escaped from it late last year. I like Eventide stuff.

I bought the Max for a good deal a while back and found it to be pretty good, but ended up selling it eventually.  I was using it as part of my guitar rig for mostly delays and reverb, but in the end i decided I could do everything I needed with my FX8, so I sold it.  The thing with the delays that bugged me is that it had a ducking delay algorithm, but with the FX8, you can set ducking parameters on any type of delay, not just the one algorithm. H9 you can't just pull up a tape delay, dial in the tone you want and set it for ducking as well.
 
I never really edited things on the pedal itself, but it looks like you really need to use the app to dig in and edit.  I used my iPad via Bluetooth and it worked well.  I have heard there are some things that are either not available without the app, or at the very least pretty hard to menu dive and get to.

At the top of my list too. I love the Bluetooth aspect.

I got one a year or so ago (the middle model). The difference between the models is indeed just the algorithms it comes with - Max comes with everything now and everything they release for it in the future. If you buy enough algorithms for a lower model (at $19.99 each) you get upgraded to Max, but there are a lot of algorithms you probably don't need. With the middle model you get to choose 2 additional algorithms for free in addition to the 9 that that model comes with. The algorithms (except for the H9 exclusive ones) are the same as the ones from the PitchFactor/ModFactor/TimeFactor/Space stompboxes, so you can watch the demos of those as well.
 
Controlling via iPad is great, but midi parameter control not so much IME (but I can't remember the details - if you want me to check something let me know). When using the apps you can audition each algorithm you don't have for 5 minutes (each) per day. It really wants an extra momentary footswitch and an expression pedal that would have been better if built in.
 
It does awesome "over the top" effect reverbs but they can of course be scaled back if you don't want to be swimming in reverb. In general, there are a number of really good and fairly unusual effect algorithms available and IMO that's this unit's strong point. I probably wouldn't recommend it over the competition for more generic stuff as it's a one-effect-at-a-time deal and pricey. 
 
By my recollection not all of the algorithms are true stereo and unfortunately the docs don't show diagrams of the routing, so keep that in mind.
 
You should be able to find them new for 10-15% off the prices you listed from a reputable dealer.

Thanks for that info, Drew. I like the pay-as-you-go model. I don't have much use for over-the-top reverbs because I'd be using it solely for live performance. Delays and choruses are mostly what I need.
 
Another thing I like is it appears to be small enough to sit atop my Kronos. I'd prefer not to set it on the floor (too many things down there already). How's the resistance on the footswitch? Could you activate it easily with a finger?

bitflipper
Thanks for that info, Drew. I like the pay-as-you-go model. I don't have much use for over-the-top reverbs because I'd be using it solely for live performance. Delays and choruses are mostly what I need.
 
Another thing I like is it appears to be small enough to sit atop my Kronos. I'd prefer not to set it on the floor (too many things down there already). How's the resistance on the footswitch? Could you activate it easily with a finger?

They're soft touch switches, so you'd have absolutely no problem there. The midi ports are on the left side though, so factor that into your plans.
 
Also keep in mind that it's, let's say, a little bit different than most FX units. Lots of algorithms have unusual parameters and sometimes things are unexpected: Who'd have thought you could use a multitap delay as a reverb? Or that a reverse reverb could make a nice delay? And what about the fact that the Resonator (with 4 comb filters) can be either a delay or a reverb - oh and if you use an expression pedal to modulate the comb filter frequencies you can get a chorusing effect while the pedal moves. 
 
It does normal effects of course, but as an example even the mostly straightforward Chorus algorithm has a secondary LFO that can modulate the depth or the speed of the primary LFO (or both).
 
But I don't take you for a "more than one knob is too complicated" kind of guy, so you should be OK with all of that. 

I use several H9s and really like them a lot for what you can get out of these boxes. I use them on bass, synths, drums as well ...
 
Some things to be aware of ...
... it's only one effect at a time
... meaning you want to use 2 of those effects, you need 2 H9s ...
... they only connect via analog connections i.e. using several will be AD/FX/DA => AD/FX/DA adding up latency ...
... latency depends on the algorithm you select (in the range of 1 - 2 ms) ...
... total latency not noticable when playing 2 H9s plus another box for amp sims in sequence like I do in my live rigs
 
When buying one H9max up to 4 later H9core (much cheaper) "max out" by themselves i.e. you get all algorithms on all (up to 5 H9s) ...

Bit, I ended up with 3 H9s, plus a PitchFactor.  I use them for guitar & keys; series & parallel routings.  Something came to mind about finger-activated switching.  You could use any single momentary Aux switch, including a sustain pedal (plus an expression pedal), or a triple Aux switch.  You're going to want expression control (or MIDI).
 
As drewfx1 alluded to, the algorithms are deep.  Deeper than you'd think.  I'd consider nearly every one to be a "multi-effect".  Some are less obvious than the others labeled as such.  For "normal" FX, like modulation, the rule of thumb is to tweak the top row, and zero out / neutralize the bottom row of parameters.
 
There are some errors contained here, but this - along with the 5-minute store demos per 24-hours - should give any tweaker worth his salt a good idea of the potential.
https://www.eventideaudio.com/products/algorithms/index
 
I'm pretty active at the Eventide Forums with preset construction, pushing the envelopes of the algos, and general operation.  Feel free to dive into minutiae or esoterica here.  Over there, it's "brock", and the forum search function actually works.  https://www.eventideaudio.com/community/forum/stompboxes
 

Here's my 4.75 cents...  
 
I use the same system for my live and studio performance needs.  Two amps.  I front end both with a few compressors, a few dirt pedals..  I play country so its usually clean.  They are controlled by a GCX unit - and a GCP.   That said - I use an H9 following the compressors and dirts to front end both amps.  I usually use pitch, chorus effects up front - sometimes slap back echo. Then we have a separate H9 in the effects loop of both amps. They take on the time based effects like echo n verb.  I did two separate effect in the loops to eliminate the chance of buzz you get going from stage to stage.  I haven't had a ground buzz since. The GCP controls all three plus the other stomp boxes. 
 
My racks take a beating - but those H9's have NEVER complained AND I have never had to reload them from backups because of a loss. I DO reload them for show verses studio work - and that has made a TON of difference for me. 
 
The effects are stellar - however, every so often, I dial up or create an effect that has artifacts in it.  Sometimes they are annoying, sometimes they support the art. Last night I was working on a part where the artifact sounded exactly like a cricket - and it fit perfectly, at a tail-out section.  You can dial out the problem in a heartbeat if you want though  - and that's the reason I appreciate these little hoober doobers. 
 
At sound check, or in the studio - you are an iPAD (or whatever flavor handheld unit you have) away from tweaking set list or individual presets for a show OR inventing the correct pallet of sound on the fly in a studio - and doing it without bending over, with one hand,  and in record time.  If your tracking in a pay environment, this becomes golden in my book.  The presets are a bit wet for my liking, but PERFECT as a starting point.  
 
I may have glossed over that tweaking set list part..  You can arrange and store your presets so that they are in order of your set lists.  The GCP does that for me now, but in the beginning, the show order was always set up on the H..
 
I bought the bargain basement one first.  Then 'bought up' to the MAX.  Once you have MAX on one unit, you get to MAX out (I believe up to 5) any new H9 you add to the arsenal.  PLUS you get new algorithms for as long as they make them.  I've had them for at least 3 years, and knock wood - they are still developing effects.
 
SO - START with the bottom unit - that 499 is well spent and it will serve you well. I firmly believe, it will fit its way into your structure quickly.  Maybe even cause you to save a few lunches a month to buy an effect. Your a solid musician - I bet you'll get more out of the one, than most get out of a gaggle of them. 
 
Take care and play on...
 
LL