I have been playing with the 6.5 kitchen for a few days and I think it's great ... Titanium doesn't seem to be very useful to me until we get a good customizer app ... Neither does the new fullscreen start menu ... Everything else is lovely though and I'm using WA3 and SPB MS3 so those are both moot points ...
It may have a few issues but I think we can stand to just work around them for now considering all the nice changes to the standard wm gui elements and some other things like the new contacts app and PIE ...
It seems like the overall speed of the OS has improved as well ... and the kinetic scrolling/panning is to die for!!