I've never tried the TF701 but my roommate has the Tab S and I gotta say, the thing is gorgeous. Looks great, runs seamlessly, and quite honestly, makes my Nexus 7 look like a piece of garbage. I imagine the TF701 similarly blows my tablet out of the water, but I digress.
I'd say the biggest difference, aside from age and possibly lack of support soon, would be the docking keyboard that the ASUS comes with. You'd have to buy a separate one for the Tab. Still, I'd go with the Tab, largely because if I wanted a tablet with a laptop form factor, I'd probably just get a laptop.