For some it depends on the time of day (i.e. 11:30 PM to 3 AM PDT is heavy maintenance stuff [backups, etc.]). But we have been under some heavier load lately as well. The last couple days should have been better than Sunday-Monday. During those times there was REALLY ugly load, but it was while I was doing some more tuning to minimize the impact heavier use of the site has, and allow for quicker recovery. Some slowness may even be related to that tuning. If so, while it does make it slower, it allows the server to recover much quicker when it gets bogged down. But I'll see what I can do.
I am also planning to upgrade the site to a new server soon, that will help a LOT in that regard (much more memory and faster processor). But that may be a month or two away.
-Alex