Hi,
Since we received a message on the users list about this, I made some comparisons between 2.6.0-pl2 and 2.5.4. I am quite surprised to see 2.5.4 being 3-4 times quicker in routine operations like cookie login, changing db, going into Structure page for a table, etc.
Removing all the js setTimeout does not improve the situation much. (Those could be eventualy made conditional to the Safari browser.)
So I am hunting to find what happened.... Stay tuned (or help me :) My goal is to restore 2.5.4 speed for 2.6.1 !
Marc