TBH if i was to get the K04conversion on mine, there is absolutely no way i would do it before i got a LSD. i can spin the wheels easily now.
....But don't be convinced that a LSD diff (ATB to be pedantically correct) will stop all wheelspin - It will only help get it more quickly under control when it does happen and it's only one piece in a jigsaw of mods which help get the power down on FWD and one of those pieces is your right foot.
An ATB diff does play a big part though and the new Sports Differential (optional extra) on the Audi's makes the quattro much more exciting.
It makes all the difference to train your right foot to apply throttle progressively and never to jerk or stamp on it - An action almost guaranteed to induce wheelspin in any gear if it's at all slippy, white lines included.
Great as it is to have big power, there are certain advantages to making progress with slightly less power delivering more traction.
We each have our own preferences but I like FWD and the more predictable RWD but get a bit bored when driving AWD/4WD. Yes you can go quicker with 4WD but it's not so much fun imo.
I wouldn't switch off ESP on the road - There's simply too much which can happen unexpectedly which has the potential to seriously damage either the car or people or both and through no fault of your own driving. And I do wonder if in the event of a serious incident or insurance claim, the fact that you were driving with ESP switched off could go strongly against you. Rightly or wrongly, ESP is considered by the authorities to be a very real contributor to the reduction of accidents.