Figured I could weigh in as well. Like others have said, you need to experiment around and see what glue makes most sense for you. I am impatient, so I mostly use gel CA, even on somewhat larger models up to 3 lbs. As others have said, CA can be brittle, but so long as you are aware of its limitations, it tends to be fine. It's good under tension, ok in compression, and horrible in shear. Most of the time, the balsa or plywood breaks before the CA bond if the CA is used in the right application. The Gorilla Glue brand gel is expensive compared to larger bottles or the stuff you can get at the dollar store, but it seems to crack less easily in my experience, so for parts that experience larger loads, I prefer to use that if I use any type of CA. Beyond that, as others have mentioned, epoxy is much stronger, so for something like a wing spar, or if you're building a big airplane, it is definitely the way to go. Finally, something I haven't seen mentioned here, but that is definitely worth considering, is tape. Obviously, this is not for the outside of a plane, but internally, there are situations where using tape, often with an extra adhesive of some type applied to make it stronger, is by far the best option. In pure tension, tape is stronger than most adhesives, and so long as there isn't a force trying to lift it away from the surface it's connected too, tape is a quick, easy solution. In situations where tape is good, adhering a layer of cloth with CA or epoxy is always better, both for strength and weight, but it takes more time.