I'm getinng nearly 3200 FPS with the 105 A-Max and nearly 3000 FPS with the Sierra 107's with a standard .243. I don't know if an AI will go much faster than that and I really doubt it will be 200 FPS faster. The nice thing about the AI is that the cases will last longer due to far less case stretch.
I twisted my barrel 1:7 so I can run 115 DTAC and Berger bullets. I've got a bunch of both, I just need to find some time to play with them.