I will add on to what was said:  I had a friend come over to play around with Bias.  He has gobs of amps and pedals, and mentioned often that "this one doesn't sound like mine", or "I know what this should sound like, and it is different than this!" but the end result was wonderful sounding amps and FX, just a bit different.
 
I could care less if the Matchless DC-30 in Bias doesn't get quite as dirty as a real one, or the modulation in the phase 90 is too fast.  It sounds freaking amazing.  They are not the real thing, they are different.  Both sound wonderful. 

I am glad you brought up Bias Amp. I had never heard of it before and I don't go looking for amp sims. I am just not an amp sim fan, although I do have S-Gear (early adopter so got it kinda cheap), amplitube free), Guitar Rig 4 (came with Sonar), TH2 (came with Sonar) and ABG (early adopter and got it cheap). It is not that I don't like the end results but I just don't "feel inspired" playing them as I do when I play my real amps. 
 
Anyway, I finally downloaded the Bias Amp demo. Wow! It is pretty good. I still do not like the clean tones. I have yet to find an amp sim that I like with a clean sound. In the context of a mix, they would all sound fine.
 
I have been frustrated with my tone micing my amps (I don't have a good selection of mics) or using speaker IRs. I do like Bias Amp though. I know Sonar is getting ready to include TH3 Sonar Edition but I did not care for TH2. Again, not that it is bad. It is good. But Bias Amp... I may have to buy the standard edition. 
 
Thanks again for pointing this out. 

TH2 Producer came with Sonar. The full version is a little different! I have long been an advocate for TH2 based on the Brunetti models that come in the full version. For my uses, they made the upgrade from Producer worth every penny.
I have Revalver, Guitar Rig, Acme Bar, Amplitube 3 and 4. I tried S-gear and it seemed a little light on features for the price. I intend to give BIAS a whirl this year and see how that works out right after I upgrade TH2 to 3!
Lately, all my bases are covered with TH2 and Amplitube 4, usually for the Fender Collection. There is a real vibe about those Fender amps!
As stated, none of these amp sims guarantee you REAL amp satisfaction. They just sound close enough that dragging out that amp and mic and getting evicted by your neighbors is not a worry anymore! Muchless, switching amps after the fact makes for a much more enjoyable music-making experience!
These are all tools. Get the best one you can and crank 'em up and enjoy!!!

Is BIAS Amp better than Revalver 4 in your opinion?

Well it seems they got everything back up and made some new releases while I was away. Not the releases I was expecting though, but they tell me they are coming. Was a little disappointed about that, and a bit iffy about the Archer (PRS Archon) set, but that all subsided after I purchased them all and installed them. Totally awesome work again, the Archer is kick arse, the Peavey full of awesomeness, and the Orange, oh the Orange, certainly makes Amplitubes Orange look a little sad, freaking beautiful.
 
Amp 3/4 had my favorite Orange, but unfortunately it was bugged, IK new about it, kept saying they were on to it from it's release all through Amp3 and into Amp4, still hadn't fixed it before I ditched Amplitube.
 
Also PG have changed the installation procedure, which was up until these were released manual and a bit of a PITA. BIAS Amp get an import presets function recently, unless I never noticed it before and Choptones didn't utilize it, but it's an automatic affair now so much easier, although if you like everything all neat and tidy you will have to do a bit of shuffling in the order. it was a real pita before, but well worth it in the end. For me that's the weakest point for BIAS, the preset management, and no standalone, but the standalone is supposedly coming and I wouldn't be surprised if the preset management didn't get a boost in the near future.

If anyone wants to get BOTH Bias Amp Pro and Bias FX Pro cheap
I have them for sale at a special price if you buy both today...

http://www.kvraudio.com/f....php?f=43&t=444861