incrediBILL - 8:40 pm on May 11, 2010 (gmt 0)
what slows it up for me, is the checking the compatability of extensions when you fire it up
Just go into TOOLS > ADVANCED > OPTIONS > UPDATES and click off "ADD-ONS" and that problem is gone.
You can still manually check for add-on updates from TOOLS > ADD-ONS using the FIND UPDATES functions.
I probably reload the browser once a week so it's never much of a problem ;)