In addition to TH2 and Guitar Rig 5 I have PodFarm 2.5 and I feel I get really great tones from that as well. It's actually my first go to.

The fact that Sonar provides us with these really powerful/quality guitar effects kind of blows the theory that Cakewalk is pandering to the bedroom hip hopper out the door. As someone who's main instrument has been guitar for 23 years I find Sonar a great recording tool for all my chunkety chugs and tweedledy dee dees. The lite version of GR that came with X1 was a little lacking for what I like as far as sounds but having that upgrade path to GR5 saved me a good chunk of money and although I've moved on to mostly using TH2 I still use it for my bass tracks. It's also crammed with a lot more options than TH2s full version so I'm sure I'll definitely be using it again in certain situations. I even like using it on other instruments/tracks such as putting some hair on aggressive vocals. TH2 however is just great IMO. Much more realistic and truer to my old live sounds. I upgraded to the full version and at first I was exactly impressed with the extra stuff. It seemed that it wasn't like the GR upgrade where the lite version was next to unusable (for my needs) and the upgrade brought it to life. The TH2 upgrade just seemed to be the same level of quality but MORE of it. But now that I've played around with it more and started building my own effects/amp chains I'm not just trying dial in my old live sound as best I can... I'm creating NEW tones that are above and beyond what I used to squeeze out of my amps. I particularly like the Overloud Custom and Brunetti heads and the Tube 9 pedal has now become my preferred distortion sim over my long time favorite the Metal Zone. The Metal Zone sim and hardware versions both have a tendency to be a little "mosquito-y" if not dial in right but it's one of the few effects that gave me the level of distortion I want without turning into pukey/noisy mess. The Tube 9 is giving me the sauce I want without that thin squashy sound the MZ does. Now that I have hooked up my Line 6 head to my interface via the XLR outs to shape the input signal I'm getting very very nice and realistic tones with minimal fiddling. I couldn't be happier with that addition to Sonar.

Sadly I missed out on the Amplitude stuff. I would have like to hear how that stands up but I doubt I'd use it as I'm guessing it wouldn't hold up well to the Overloud modeling. Maybe I'm mistaken on that.

Anyway, it's just nice to have that extra stuff in there. It took a lot of extra worry and expense out of my software purchases.

As far as continuing to invest in Amplitude... well that's just a matter of what you like. If it's working out for you then why not take advantage of upgrade prices? The more tools the better. Like I said the included version of TH2 is pretty usable on its own so unlike other stuff an upgrade isn't really necessary... however there are indeed LOTS of cool sounds in the full version. You can get lost forever poking around at it. Before X2 I would NEVER sit and play through my DAW just for practice/pleasure. It just wasn't as fun because the sound wasn't as good. With GR the guitar tones didn't come through until tweaking during the mixing phase. With TH2 I get sweet fun tones pretty much right after plugging in. 

JMO

Unless they've gone beyond the Demo version of Guitar Rig, I don't think most people realize it's potential. You can add all kinds of effects to it, use it for vocals, pretty much anything. Think of it as a Pro Channel, but in a VST format that can be used in any application.

I've never seen the Amplitube sim? I've seen people talk about it, but I've never been able to find it in Sonar. Maybe it doesn't come in the Producer Edition?

Another Amp Sim that people overlook that sounds just as good, some people say better, than all of them is the Cakewalk Amp Sim that's been included for years in Sonar. I still use it t this day. Pair it with Z3ta and you can get some incredible sounds out of it. And the Reverb's in Z3ta are excellent. People don't associate it with being an Audio FX because it's a synth, but it can be used in that way.

There are some amp templates in Sonar that include Z3ta and the Cakewalk Amp Sim.

TH2 sounds good for clean stuff to me, but I still prefer Guitar Rig over it.

Another thing about Guitar Rig ... there is a setting in the very upper right hand corner to increase CPU usage. It helps the sound a lot when you enable it. It's off by default, but it does suck up CPU usage.

The main reason I HATE AmpliTube(that I've stated ad-nauseum) is because you pay for a lite program and they nail you with add-ons... and it doesn't sound as good, IMO, as GR5/TH2/Scuffham.

When I'm up late, I like to toggle through all the sounds and see what I can create. Not go on the web, browse for sounds that I don't even know what specifically they may be, then download and try so I can give IK more money?

SCREW THAT!

 I've always been a Fender guy, so when I found Amplitube Fender I bought it. It's the best (in my opinion) to a legit Fender sound. My real amps have been silent for awhile now. You can always download the new Amplitube Custom shop for free. It comes with 5 amps, 6 pedals and 2 rack effects.

You can always download the new Amplitube Custom shop for free. It comes with 5 amps, 6 pedals and 2 rack effects.

Huh... just taking a look at that now. Interesting. Cheers, Clint. Hope you've been well.

GR5 is awesome...

I'm a big fan of Guitar Rig 5.  I like the amp sims, but the effects that come with it are great, too.  I love the Psychedelay. 
 
You can make all sorts of fantastic tones.  I have a rhythm guitar track on a song I'm working on that wasn't sitting well.  After flicking through a few presets, and then a bit of tweaking, it has turned it into what sounds like a killer rhythmic synth part.
 
I have started to use TH2 a bit, too.
 
I also use Amplitube 3 free, with a few extra bits from the custom shop.  You can try out different amps etc. before you buy them.. I HIGHLY recommend the American Clean III and Lead III - they're sims of a Mesa Boogie Mark III and they're lovely.  The clean channel is one of the best I've heard.  You don't have to take my word, try it for free.
 
I also like using all three in a project to give me a variety of sounds.

What would be the correct way to get the old GR4 from X1 into an X2 installation?

Shambler, I beleive if you already have X1 installed with GR4, you should be able to use it in XE, that is how it works on my machine, however I upgraded to GR5 (why, don't know, newer is better? probly not, oh well...), so I have both GR4 from X1 and then GR5 from the upgrade. Plus TH2 which came with X2.