I can only go on a comparison of my last car, A4 1.8T (52 plate) and my current 3.2 A3.
I live in a particularly rural area so AWD is essential, especially for the lanes. I find that the 3.2 offers lots of power when ever I need it, be that ripping through the lanes going up/down gears quickly with the DSG or cruising on a motorway. The turbo lag on the old car was just too eratic for my liking. Smooth, when ever I want it power is just the ticket.
As for what power you can get out of a 2.0t, do you really want to be a) messing with your warranty and b) taking your insurance to stupidity just for the sake of choosing a 2.0t over a 3.2. Besides there is already talk of a 400bhp 500nmtorque turbo upgrade for the 3.2 if thats what really floats yer boat.