Just got my POL the other day from BBTS. Finally had a chance to get into the boxes and pull out all the figures.
I got FT Grenadier (Bombshell), Sphinx (Mirage), Tracks, and the KFC Rover/Fader (Eject) set to finish off my Aubobot Cassettes. (Well, until they remake Steeljaw and Ramhorn.) And also the replacement shoulders/rifle-extensions for Ultra Magnus, which I finally got around to installing today. Boy, are they subtle changes but make a world of difference by just adding some extra movement.
Tracks is fiddly as fuck. I like him, but he doesn't seem to be as solid as previous MPs. Sphinx is the same way, but he's got more heft to him and his transformation is less complicated, so he seems to not suffer as much as Tracks (although both of them suck when it comes to moving their shoulders/arms... shit comes unpegged, drives me nuts).
I guess I got a good copy of Sphinx, because mine's pretty solid all around. No particularly loose parts or bad apps, unless I want to be an absolute petty pain in the ass. Fader is solid, too.
Bombshell is the most impressive all-around though. Buy is that figure solid. Can't wait for the other 2 Insecticons, and I don't even like the Insecticons.