I posted tone tests of some of the high gain amp models in the new Line 6 HD Pro. Specifically the Engl Fireball and the Mesa/Boogie Rectifier. The guitars were tracked direct via USB. I used no post effects besides a low pass filter (80 hz) and a high pass filter (12k). For those of you who record guitar it would be wise to incorporate this technique. Removing those high end frequencies will help remove some extra noise, while the clearing the low frequencies to make room for kick drum and bass guitar. There are a total of 3 samples up. One with each amp alone then one with both amps combined. I doubled tracked each amp and panned L & R. Not a hard pan though. For each amp, one track was panned about 90% while the other was about 75%.
Check out one of my soundcloud pages for the tests.