I had a 7.7 prior to the mini launching. Actually a really nice piece of kit, exceptionally well designed - pity Samsung dont apply similar principles to its other lines - and the screen is markedly better than the current Mini. However, I sold it the moment I got a mini, the app's are incomparably better on the iPad.
Also, I only really truly liked the 7.7 when I rooted and bunged CyanogenMod10 on there. Touchwiz isn't quite as bad on tablets, it was slightly toned down, but it was still godawful. CM10 was far better, and much smoother.
Given how much time has passed, I wouldn't go near a 7.7 now unless you can get one for peanuts, which is unlikely - bar the Nexus 7, its still amongst the best android tablets, better than newer Samsung models too. If you really want an Android tab, Nexus 7 2nd gen without question will be the better option.