Guys:
We are discussing three distinct elements of Q500 fuse design as if it were one.

The first is rigidity. I believe the more rigid the better. If you look at the various designs the Vortex is, in my opinion, is the plane all others must be measured against. The Vortex has a ply / balsa fuse with a heavy ½”, I think, firewall with lots or epoxy/cut glass and balsa fillets. It also has several fuse formers, which in combination with the 3/16 balsa skins prevent any skin flex. The finish is glass/paint, which Chuck does because he doesn’t like plastic film but as a by-product adds to the rigidity as well as longevity. Most glass fuse designs aren’t near as rigid in any plane as the Vortex including the Nem I have hanging on the wall. The Shotgun, however, with its balsa skin / molded glass fuse is a close second. If Bruce would reinforce the firewall / front end more and add a couple of formers aft of the wing it would be very good.

The second is design. The good old Vortex does not conform to current thinking on fuse design. Both the Nem and Shotgun use a fuse design when viewed from side follow the airfoil very closely and have gentle curves. The Vortex has pretty much straight lines with a smaller radius on the corners. The Vortex does, however, have, like the other current designs, have the fuse wide point located at the wing TE. It would seem the current glass fuse designs, Nem and Shotgun, are probably superior to the Vortex.

The third is surface finish. I read a comparison a while back where plastic film demonstrated lower drag than most any other surface. I’m not sure if a highly polished, smooth, non-porous painted surface was included in the test but common wisdom would put it about the same as plastic film. I would have to believe smoother is better and a good plastic film covering is equal to the best molded / painted surface. There are, however a couple of variables. All painted in the mold fuse’s I’ve seen have a rough seam where they are joined and plastic film has overlap edges. I don’t know if this makes any difference with flow boundaries and all but the only surface disturbance on the Vortex is the servo hatch.

Anyway to my mind rigid, rigid, rigid followed by design followed by finish.

Just my opinion.
Barry