RME UFX+ vs FireFace 400

I've been using the RME FireFace 400 via Firewire for several years now and it's great.  Reliable, great drivers, low-latency. Everything I could ask for. Decent enough clean pres, but I also have a couple of more colorful preamps when I need something like that.  (Warm Audio Tone Beast and UAD LA-610 Mk II).
 
While what I have works great and is paid for, I'm considering going for the RME UFX+ and using it via USB3.  On paper it looks like a pretty nice unit and a big step up all around compared to what I have now.  More and better pres, better converters, USB3 for now, Thunderbolt for the next generation DAW I may move to in 2 or 3 years.  Lots of things tempting me. 
 
I'm looking for a bit of real-world experience here on how they compare though. Will the USB3 connection meet or exceed the latency I get with the FireFace 400? I comfortably run at 64 samples in Studio 1 on everything with the FF400, so I'd definitely need that or better, but the overall improvements across the board interests me.  Any other pros/cons I should consider, besides the outlay of cash for this unit?

Thanks for the feedback.  Those features are part of what catches my attention.  I think having that built in to the unit might make things nice for monitoring some reverb and delay while recording.  I hadn't heard about the auto level part, so that sounds kind of nice too.  I'll have to do a little reading on how that works.
 
As long as the USB3 round-trip latency is the same or better than my FF400 gets with FireWire, I may have to think this over.  Definitely tempts me, but I don't have to decide right away.

Thanks for posting those... you're too late. LOL 
I did a little more searching for videos (didn't see those, but they help too).  I saw enough last night that I did a little bit of looking around and found a pretty good deal on one and ordered it.  Looks like I'm going to be able to do some really wild stuff if needed.  I probably won't get nearly as involved, but those videos gave me a few ideas on how to have some fun with it when I get it in.
 
I think what sold me on it was a video where the guy showed a pretty full Reaper project with the buffers set at 32 via USB and it was working well.  I knew the overall preamp and converter quality would be a step up, and the Total Mix stuff would be useful, but it reassured me that I wouldn't lose anything on the latency (and might actually gain even better performance).

I use Studio One, and they added in the capability to use the low buffer setting only on tracks that you are monitoring, like soft synths or maybe a vocal track you are recording while monitoring with verb and delay, while playing back the tracks that you have already recorded at a higher setting.  Can't remember what it's called, dropout protection or something like that.  I set that to high and it basically syncs up your playback at 1024 while the live monitored tracks are 64 buffers.  Now that I have that feature I can't imagine getting by without it. :)
 
I'll check out those links as well.  I do have the main company links, but I don't think I ever joined the forum.  Been a long time since i even lurked there, but that's basically because their stuff just works and you don't have to do tons of research to get it to work.
 
Thanks, and can't wait to get this thing fired up now!

I made a similar switch about 6 months ago. I think you will like it! Although my UFX II just works with USB 2.0
 
I also use studio one 3. Lots and lots of tracks, and the soundcard sounds great. It's slightly but not dramatically superior in the sonics, but I could tell a difference and all works well so far.

I just thought of a question that Jim may know the answer for... while I'm sure I'll have great performance using this via USB 3, I was kind of wondering if my current board would support an add-on PCIe Thunderbolt card and if it would make much of a difference if so. 
 
Current PC is:
StudioCat DAW with Asrock X97 Pro Chipset and I think it's a 4700k i7 CPU.  Of course I didn't type this out while I was in front of that computer early this morning, I'm doing it from another.

I looked in the BIOS and there was an option to enable Thunderbolt, but I know it's not actually built onto the board.  Just wanted to check and see if it is possible.

Thank you

Yeah, it will be fine with USB3 on this one.  I had a couple of emails with Jim and he confirmed that I need a new board, etc to be compatible, and also said that USB3 is great with the UFX+ until I decide to get a new DAW.  I'm at least a couple of years til my next DAW upgrade, and want to make this one last even longer than that.  I'm hoping this interface will last me as long as the FF400 has, and I'm sure there is enough use left out of the FF400 that the next owner will find it nice as well.

The UFX+ arrived Monday afternoon. I have some important family things going on, so I had limited time and so far have only had a chance to play a few tracks that I recorded with the other interface. I played around with it for awhile and figured out some basics and went to bed.  Naturally midnight insomnia kicked in and instead of waking up and snacking, I got up and did some more listening and a little mixing.
 
Small issue out of the box.  It would play through a song in Studio One, and when it would finish and rewind to the beginning it had this horrible, harsh noise that would play until you close Studio One, and it would close with a crash.  Never happened on the old FireFace 400.  I double-checked that I had the latest driver, and noticed that they had a firmware update utility that I hadn't downloaded previously.  I ran that, and found that it was pretty outdated right out of the box, and the firmware update cleared things up completely.  I'm guessing the driver was a few versions newer than the firmware and it may have caused a conflict.
 
In playing back a few songs, I thought it sounded a bit different, like maybe the stereo imaging was better, highs a bit smoother and mids more detailed.  I have also been using a Presonus headphone amp what my mains were also running through, and since this has two headphone outputs, I figured I'd try connecting everything directly and bypass the headphone amp.  Even better than I first thought.  This thing sounds amazing.  I don't think I ever quite realized how much that little box changed the sound, but it took things to a whole different level removing it from the chain.
 
On the topic of low-latency and buffer settings: this thing has no problem with handling a setting of 32 samples.  I did happen to notice that the reported round-trip latency in Studio One was insanely low at 64 samples:

• 6.08 ms for audio and 4.24 for instruments.

At 32 samples, I think the audio was slightly lower and the instruments was slightly higher, but it really wasn't enough to even be concerned about, so 64 it is for me.
 
I may not have time to really dig into doing any recording until the weekend, but yeah, I like this interface.  They actually improved on the old tech I've been happy with for years, and I have a feeling this thing is going to last me quite a long time.