I found all three at the TRU on La Cienega. I think Sunstreaker's as close to perfect as I can imagine, but Prowl and Tankor/Octane have issues. Tankor I expected, because triple changers almost as a rule are problematic, but it takes some finesse to get everything to lock together in all three modes, though he is solid once you get it right. And his head doesn't seem to come up all the way. Not sure if it's part of the design or if I'm doing something wrong, but it makes him seem stunted somehow.
Prowl is awesome in car mode, but I'm having trouble figuring out how to transform him without the door panels popping off (which, in a way, is a nice homage to the G1 figure - HA!). His head is also on a joint that makes it appear as if he's looking down. Again, it may be limitations in my ability to transform him correctly, but I'm pretty sure I've got it right. He's still a really cool figure and I dig the faux shoulder rockets, even if they are blandly white and unpainted.
Sunstreaker is perfect. I have no complaints and wait with great anticipation for Sideswipe. I'm REALLY hoping they find a way to give Swipe a faux rocket launcher. I remember the original sketches showed the engine accessory as being able to transform into the rocket launcher, but that was clearly abandoned at some point. Although the gray pieces ARE on a hinge and I have yet to figure out why.