Hi Mark,
I havent played around too much or set up the GZ retracts but from what Ive seen they seem to be fairly reliable, they run off a 2 cell lipo.
The anti stall mechanism works well , if you mechanically obstruct the strut you can see the anti-stall mechanism work.
The brakes are electrical as well and completely propotional , I guess there is some kind of solenoid in the brake drum as opposed to a O ring in a pneumatic system.
As a system it seems to be working well so far barring a few issues we have had with poor electrical contact at the control unit , we had to wiggle the contacts on a few occasions to get it to work .
A Wren70 or a SS will fly the airplane BUT with marginal performance, with a P80 the vertical performance was very limited, IMHO it needs a 120 !
No wingtip options are available
Xantos