W444,
I have an RV-6 with a D100 (bus master, so it communicates with the AP) and a D10A, Dynon P&R servos and an AP-74. Been flying with it for about a month (maybe 15 hours), so these are early observations (and a caveat here...this is my first AP install, and first small airplane AP, so I'll not claim
anything like expertise in this...just observations of "Joe the Pilot"!
):
It's taken a little effort to tweak the settings for a ride I like, but I expected that, and am pretty pleased overall. I have more tweaking to go, but Dynon has been really helpful (on the phone and on their forum).
It's a pretty new product, and though extensively field tested, there is a learning curve to go through, and there have been some possible bugs (pitch occilations, heading and nav course chasing, possible play in the servo arms to name a couple) that have been discussed here and on Dynon's forum, and are being diligently worked on, both by Dynon and by those flying the AP. I've been able to tweak it to the point where most of the pitch occilations are gone, though they sometimes still happen, and heading and nav tracking are pretty darn good (for me, nav has been more solid than heading, though both are decent). I played with setting up a VNAV descent in the 396 today, displayed it on the EFIS, and then set up a 500 fpm descent with the AP, and it did a pretty good job matching my VNAV profile (not coupled of course, but it did what I wanted it to do). Flew a 2.6 X-C today, and much of it was on AP, so it did pretty well, except when it got a bit bumpy over the mountains.
The AP-74 is really nice to use...not sure if you are considering it, but for me it was well worth the $$. Lot's of nice features that I'm using (like altimeter setting, heading and altitude bug setting, mode presets, etc.). I haven't played much with controlling the AP through the EFIS buttons yet. If you are not going to install an AP-74, it may be worth asking how people like day to day ops using the buttons (s'posed to be easy, but feedback from those with no AP-74 would be valuable to the overall decision).
I've flown a friend's RV-9 with a TT, and it was really smooth. Set the bar for where I want to get with my Dynon set up, and I think I'll get there. I couldn't begin to compare TT/Trio/Dynon AP's, but I think Dynon is working hard to make their AP system a good one in a field of quality APs!
I've seen discussions of separate EFIS/AP system types for redundancy, but mine is a VFR set-up, so I'm comfortable with the all-Dynon system. Just another factor to consider, dependent on your mission, desires and tastes.
Just some thoughts from a knucklehead...hope they are of value to you!