I'm on my 3rd one of these.

Plane: CMP 3D Giles 40 size
Engine: Tower .75 (I know, but it hovers at 1/2 throttle and pulls out like you shot it from a cannon)
Problems:
Firewall is weak. It's just 2 pieces of lite ply and it's very weak. I cut it out with a hobby knife--takes about 2 minutes. I replace it with 1/4" hard ply.

It needs a tailwheel. The wire skid that comes in the kit is useless. You can't control the plane on the ground unless your constantly blipping the throttle to get the rudder to work--then you end up taxiing around at unsafe speeds.

The Stock wire gear is weak. I replace it with aluminum gear. Specifically, I buy the gear from the Great Planes 25% Giles ARF. Cut about 1" off each side (2-piece gear) and then install a hardwood plate in the fuse to bolt it up.

The pushrods could be upgraded to a heavier size. I find them to be kind of undersized for this plane. It's similar to 2-56 size and it needs to be closer to 4-40 size.

This is a longshot:
I'd like to see the fuse design changed. It's VERY weak under the wing saddle. This is because the whole top of the fuse is the plastic canopy.

Change the design so that the wing attaches from the bottom and has a belly pan on it. Build up the top of the fuse like most other planes and get a standard size canopy instead of the huge plastic piece that the plane has now.

This would add a tremendous amount of strength. The plane isn't really all that light to begin with--so changing the fuse desin won't kill it.

I know that this would involve a complete redesign of the aircraft, and also a re-tool at the factory. It probably won't happen, but it would make the plane a lot nicer. Just wishing out loud more than anything.

If you could get the LG, firewall, and hardware beefed up--I'd be tickled.

Thanks for listening. I hope this was constructive.