I've never flown one, but am very interested in the Velocity. I read a writeup from a Velocity owner who had a door pop open in flight and he was barely able to control the aircraft. The problem is that door creates tremendous drag, and makes the plane pivot around that point rather than other control surfaces... The other own modified his plane to change the doors to forward opening. (Why don't I find that link?)
Here it is: http://www.velocityxl.com/wiki/index.php?title=Brim_N87BR
If I ever end up buying or building one of these, I think that's a mod I'll definitely plan.