Overall phone responsiveness seems to be quicker, overall I don't think there is a big difference in how fast the phone app or music app work to be noticeable. But moving between screens, the app drawer, loading apps....all that is much quicker/faster.
I run at 1050mhz and get a good full day of use out of it. I'll flash a ROM, run a backup, change a kernel, browse the market, handle 90% of my emails, run Wi-Fi 40% of the day and GPS 100% (turn on anyway). I don't play games and I don't talk a tremendous amount on it. It's email/web/messaging/app searching is mostly what I use my phone for.