since gui still not smooth as it should be, and in heavy projects zooming still painfully (but bettern then 9.0 ).
i found some soulutions to make it less laggy
File-Preferences-Show Event Display:
Show Event names - disable
Smallest track heigh to show data - three rows
Smallest track heigh to show names - three rows
after this,project zoom not more then three rows, gui will be smooth as should be. dont know why fonts & midi/audio images reduce gui smoothnes.
show only 1 track at your working on, hide others.
Freeze/Bounce instruments/audio - yes, more CPU loaded, less smooth GUI you have
hope it helps.
if you know other tips, welcome