I have flown many of them, sig, goldberg, great planes, and balsa USA big one.

The goldberg is by far the best flyer. The great planes would be next and the sig my last choice. I have flown probably 20 different goldberg kits, and every one flew awsome, not one, even the one that was built really poorly had any bad flight traits. I have only flown one great planes, and it wasn't bad, but not as nice as the goldberg. I have flown about 4 sig cubs, 2 were ok, and 2 were not worth flying. I don't know what the deal with them were, but they were not fun to fly, didn't track good and just miserable to land. Never flown a cub that was that big of a pain. They could have been really messed up when built, but didn't look to be.

Just my exp with them.