I use it exclusively and the only "problem" I ever have is occasionall some CSS doesn't display like it does in IE. Play around with some of the settings and see if those help. Also, the ebay content issue...if you have an ad blocker it may be blocking some stuff. It depends on if you got a build with a bunch of extensions already included or if you got the plain ol' firefox.
Also, which version are you using, indy?
-j