I think the Torpedo Two Notes is about as "realistic" as you can get with a TON of options... however, I personally LOVE the cab sims on my Lexicon MPX-G2
Yup, will be difficult to obtain a better IR-based sound than with the Torpedo's.
Note that the Torpedo CAD is much more than just a cab sim; it features separately selectable emulation for amps, cabs and mics.
Amps aren't amp models, but rather four different tubes in triode or pentode couplings, gain, sag et al.
Cab IR's can be installed, mic selections are fixed, but with adjustable distance, angle.
Didn't know you have an MPX G2.. I also dig it's analog cab sims. Only a few seems a bit too bright, but that's the graphics EQ are there for