Had a Sig and a Great Planes.
The Sig is a more complex kit- for the craftsman. I seem to remember cutting plenty of wood for that kit. The GP went together real easy and is a better floater than the Sig (possibly due to my building skills 20 years ago on the Sig)
The GP has a better cowl, windows, landing gear (lots of wire bending and welding and/or silver soldering on the sig gear- although you ended up with a more scale-like setup)
Between the two, I'd go with the GP. Goes together quicker. Flys better than any trainer with a .45. Plenty of room to hide the guts if you want to do a "scale-ish" interior.
Here's some pics before the cartwheel landing.[:@]

Tom

www.poconopa.com/cub2.jpg
www.poconopa.com/cub-engine1.jpg
www.poconopa.com/cub-bot.jpg