Have the same dilemma myself, leaning towards the polo as it's still big enough for me and the new engine and manual option is way better than the old twincharge/dsg combo of the previous polo. Brand new car too so longest possible warranty over a 12 or 13 car. Have heard that the new one with a stage 1 tune will able to be as quick as the mk6 golf gti with an equivalent stage 1 tune. Drawback on the polo I'd say as most have mentioned is the handling is probably not as good as the golf as its a solid rear beam I'm pretty sure