The GSG is cool looking and fun.
The 10/22 is inexpensive (usually, few companies beat Kel-Tec on cost) and very flexible and can be accessorized and modified to the extreme, but those mods come at a cost. I have a friend who had a very nice 10/22 with upgraded sights, a match trigger, and a stainless bull barrel. No scope, and he had $800 in it. He sold it and couldn't get his money back of course.
The SU-22 is very nice right out of the box, because of the high end SU-16 parts, and Kel-Tec offers a couple of stock options if you want to mod it. Hopefully, they'll offer the Charlie underfolder and the AR-style pistol grip collapsible stocks as factory options instead of making us buy the alpha stock with the rifle and then buy the charlie or AR stocks to upgrade.
I can say that I've already gotten my money's worth out of my SU-22C, and it's been my favorite gun to shoot the last 22 months. Everyone else likes it too. Tons of fun! It's a keeper!