Someone will come on and say "I do!".
I've only used it to repair a hollow-fuselage profile that has been on it's last legs for several years and dozens of flights. The last "last legs" problem was that the fuse was starting to delaminate around the wing. Peeling off and patching the outer layer would have been a pain, so I just shoved the tip of the glue bottle into the break and put in some glue -- from the way it foamed out I'm sure it filled that compartment.
I haven't tried it for a nice plane because it's hard to control the amount of foaming you get. the foaming is really nice when you have gaps to fill, but a pain when the job is done and you have all that glue that you need to chip off or make excuses for. Particularly given that the glue is much harder than the balsa you're trying to chip it off of.
If you're gluing the usual music wire 'U' shaped horns, then you almost (only almost) don't need glue at all -- in fact, when you use lucky boxes, you don't glue the horns to the surface at all. The most secure way to glue these would be to sand lightly, then immediately epoxy them into the hole. CA glue would probably work for a while, but I would expect it to break out before the rest of the plane was worn out. I've always done this with epoxy.