I've looked at the AQ-6 and really the only thing stopping me from picking one up is the somewhat weird and lengthy setup process you have to go through to get one flying properly. Lately I've been having fun with the new generation of Multiwii boards, the 2.2 firmware release is light years beyond the 1.7 that I started with on a Quadrino board a year or more ago. The fact that new sensors have also made the boards far better at leveling and position/altitude hold help tremendously as well. I currently have one of the Mega boards on an F450 frame with a Ublox6 GPS and this thing flys better than a Naza in Manual, just as good or better in autolevel, and GPS position hold is pretty darn close too. All that for around $85 inclusive of the GPS, how can you not like that deal? Yeah you do have to tinker with the tuning a bit to get it dialed in but the new firmware and sensors really do minimize that, I'm not that far off default settings and it flys beautifully, it's become my second favorite FPV quad behind my heavily tweaked TBS Discovery.
I've got a brand new "real" APM 2.5 that I'm considering mounting on the Cinestar frame to see how well it handles that. First I think it's going to spend some time on the Droidworx AD-6 until I get a feel for how it wants to be tuned on a large hex hauling some weight. I have spares for the AD6 and though I'd be PO'd if I crashed it, not nearly as much as I would if I crashed the Cinestar and did substantial damage.
One of these days I'll get around to updating the firmware on the YS-X6 and give that one a go again too. I parked it mainly because the gimbal stabilization sucked badly and that was pre-RSGS days when the only alternative was an unobtanium Picloc so there really was no alternative for APV + YS-X6 at the time. Now that I have the brushless gimbal I don't need the built in stabilization so suddenly the YS has become a viable alternative again.
Ken