For the first time ever, I think, staging over to a new server worked just perfectly for me. I upgraded our mail server to a new system for work over the weekend, and it looks like everything worked the first time.
We're going from a single- to dual-cpu system, with a much nicer raid setup. Load has dropped dramatically, and response-time is much nicer. Other than when I'm running backups, load is staying around 10% (well, this is Sunday, probably 15% tomorrow), which gives us plenty of room to grow.
Did you see yesterday’s slashdot article about webserver load handling? Interesting stuff.