First - apologies for the poor video. I'm running a $30 gimbal on a standard Martinez without tuning, and a TBS with a mysterious vibe problem. I've left prop sound in, so you can hear the motors misbehaving.
Ok, my previous forays into autotuning have not had great results; today was better.
I ran autotune on my testbed, and it was done in about 3 minutes - super quick. Looked pretty tight in the air...until I tried the settings for myself. It was way too floppy, like the APM was loose or there was a drunk driving it (not me!). It was downright dangerous. The PIDs were way soft, so I tweaked them. Was much better after that. A few tiny tweaks to go, then I can start thinking about optimising the gimbal.
The Disco took slightly longer, but was strange - too aggressive on pitch, too soft on roll. Mad oscillations when in fast forward. Pitch P was tuned down, Roll P was tuned up, and D was tuned up on both. Much better. Now I just have to find that damned vibration...it's driving me mad, and the video is unuseable! Using a TBS Loveseat, but might try switching to moongel for a while.
I think I'll continue to use autotune, even after the crashes...it's not perfect (for me! Your mileage may vary), but it's definitely a quick way to get to 80% right, then it's a quick tweak or two to get to optimal. It's also a high risk way of highlighting any deficiencies in your airframe...