So I just wanted to post on here about my experience with Rev 4 and the ACT EQ. I have a 6505+, and recorded from the amp into Ableton, and used the Fractal Audio Cab Lab with the Zilla IR's from Misha Mansoor. Then with the Revalver, I set it up with the 6505 block, and the 3rd party vst block running the same cab lab IR. Then with the ACT EQ effect, I profiled my real 6505. Straight up, it is absolutely indistinguishable. I have not had time to upload a comparison, but I will when I have the time. The interesting thing about Revalver cloning technology vs Bias, is that you have good articulation and pick attack, as opposed to Bias where things tend to get too muddy and compressed. This is just my opinion, and I dont think Revalver gets enough love. If you know what you are doing, and know how to adjust the schematics, and properly use the ACT EQ, I think Revalver can sound incredible in a mix.