Under Windows, the right click menu on links takes a few second to come up, and often when typing in text windows, the cursor falls way behind like I'm typing over 300 baud modem. And yet the CPU and memory usage is low.
I'm sure I've mentioned this before, but I can't help but wonder if Firefox is falling in to the same trap Netscape did. Netscape was perpetually trying to get new features out before Microsoft, and they focused on that at the expense of fixing bugs, so while they had a lot of feature, the browser was completely unreliable.
I feel like Firefox is starting down that same path with Firefox 3. They are all about features, with no shame when it comes to releasing a buggy browser.