A friend of mine just bought the AR-7, and it's a pretty cool gun. Lots of storage, and it's watertight and therefore floats. The front sight is cheap orange plastic which slides from side to side - I'm not sure what the purpose of that is. His is a little picky with ammo, too.

I think the Ruger takedown 10/22 would probably be more reliable, and it doesn't take up much more space than the AR-7.

If you want/need watertight, go with the AR-7. If not, I would go with the Ruger.