Just installed the FF update to 3.6 beta 1. Haven't notice an difference as of yet. Will be testing for a few hours; will post back later as to the stability and if any problems occur.
So far one of the minor problems to note is the inability to load Some themes, and add-ons. Now remember this is a beta 1 so there are still going to be some problems.
Most of the theme section is grayed out, hence there are only a couple of themes available at this time. Also in the add-on section the only add-on available was ADBlock Plus; which was the main one that I use so there was no problem there.
Most add-ons had the following tag: "This add-on is for older versions of Firefox recommended."
If you are looking for benchmarks then you are in the wrong place. Benchmarks IMO are not important. Never have paid attention to them, otherwise I would probably be on Chrome or Opera.
Once Again this is a Beta 1 release. More later. Add to Firefox