I believe I've seen what Hawaiis was referring to on my 15m: If you pulled the trim all the way in, and pushed the bar all the way forward, the tips would fold in occasionally. They immediately popped out though as soon as you pulled in any power, and it didn't affect stability.
I did some tests with the new 9m & 18m, and couldn't get the tips to fold at all. I also did some stability/overshoot tests, and like Andrewjohn says, it just kind of comes up then settles back back without ever overshooting, even when flown through the power zone. I've got some pretty boring video of my 9m test available on youtube: the de-powered stability can be seen around the 1:50 mark: https://www.youtube.com/watch?v=n-c2SbWlydI
Hardwater, I always appreciate side-by-side tests (the Access/Peak comparison was great); glad you're getting a chance to test them both out.
I'm falling in love with my 18m for low-wind cruising and boosting. I've got a bad back, so the floaty jumps and soft landings are a huge bonus.