I'm using the Torpedo Studio with my Mojave Scorpion & Orange Rockerverb 50 MKI. I seldomly use the Two Notes power amp simulation, because both these amps deliver a pre+power amp tone and there is no way to isolate the preamp signal from these amps (the Mojave uses a line out which already has the power amp part in it and the Rockerverb has no line out). I only use the Two Notes power amp simulation if I'm playing around with Axe FX II amp models (in that case Sag=0, i.o.w. power amp is defeated). This technique is nice to get a different flavor, but overall, I prefer the Axe FX II power amp sim, which in no way implies that the Two Notes power amp sim is bad.
What I do like about the Torpedo is that you can move around the Mic and instantly switch IRs that way. Sure, you can load about 100 IRs of a single cab and do the same process in the Axe FX II, but it's much easier to do it in the Torpedo.
In my opinion, the Torpedo should not be bought if you'll only use it in conjuction with the Axe FX II, except if the convenience factor means so much to you. If you have real amps lying around that you'd like to use at high volumes and/or if you don't want to mic your cabs, then the Torpedo is a very nice tool to possess.
As far as IR quality goes: The Torpedo IRs are as good as Axe FX's High Res IRs. However, Two Notes is not offering any IRs in the "Ultra Res" length, because Guillaume Pille, the inventor of the Torpedo, is not convinced that "longer" IRs sound better than the "High Res" Irs. You can however convert Ultra Res IRs into the Torpedo format. But if you're convinced that Ultra Res IRs are much better than High Res IRs, it's best to stay with the Axe FX II.