I am a big fan of Firefox and was extremely happy with 3.6. I am sure I'm not the only experiencing multiple problems with Firefox 4.0. Ever since I have upgraded on my MacBook Pro (OS X Snow Leopard - 10.6.7) pages load at about 10% speed on a GOOD day. Any kind of applet doesn't run or runs incorrectly, especially java. It feels sluggish and so much worse than Safari now. It used to be my default browser but no more. Awful.