Has some neat features that I like, but I miss the drop down feature in the address bar that shows your last few visits to other locations. On the other hand, the opening screen shows mini-windows of the last six sites visited, which is in some ways better if not quite as convenient.
Only problem I've noticed is that when checking e-mail in MSN's hotmail, I can't open one, whereas when I log in with firefox it opens right away.
Also, Sun has made a MS compatable office suite available for free, at OpenOffice.org. Free spreadsheet, word processor, data base, presentation software and more. So far no problems with this at all, don't even use Excel anymore.