I use at least 12, five on each side and two diagonally to hold them on. If I am planning on doing anything aggressive, I'll throw on another pair.

Given that the Avistar is meant to be a bit more aerobatic than the typical trainer, I think 14 is reasonable. I also buy them in bulk at Staples and throw them away after every flying session.

With four bands, if you pick up the plane by the wing, the fuse will lag behind by a couple of seconds. That's just crazy.