I’ve been using GMail a lot lately. I’ve shunted my public-facing e-mail address through it, and the spam filtering has been surprisingly effective. I’m also interested in the AJAXy goodness they’ve implemented, which gets around some of the interface headaches inherent in Webmail.
Unfortunately, I’ve noticed something disturbing when using GMail in the same context as a traditional mail reader. It doesn’t seem to respond well to multi-tasking. Specifically, if I try to fire-and-forget something (like “Archive these three messages”) and switch to another window or tab, GMail stops acting on my request and gets stuck on “Loading…” or similar.