Despite the nightmare stories I've read about Vegas 11, I upgraded today from the old reliable 8c. I needed ACVHD editing and Premier is just awful. I've never had any of the problems others have had and I've been with Vegas since 4 but so far I've noticed the preview bogs down and/or freezes up momentarily. This is the first I've used Vegas on a laptop so I'm not sure if this is a Vegas issue or system issue. I'm using only the onboard SSD right now and I confirmed that GPU acceleration is off.
I'll tinker some more. Right now I'm just glad to be rid of converting everything from AVCHD.