Well, my Gti was in at the worst VW dealer in the UK recently (i'll not say who, but they aint far into Scotland). I took it in because it was running on 3 cylinders - they upgraded the ECU soft and sent me on my way. Did it fix it? No. So I took it back and they then decided that 2 of the coils were faulty (the engine management told them this the 1st time, but they though it was wrong!?!?!!)

Anyway, ever since the software upgrade I have notitced a difference in the behaviour of the car when hashing it through the gears. (its a 6sp manual)
Before: Slamming into 2nd or 3rd would induce slight wheelspin and then the TC would kick in and cut the engine power, leaving you with your boot on the floor and a dropping rev counter! Useless - and used to annoy the hell out of me.
After: TC very much more forgiving now - will allow slight slip without kicking in and knocking the wind out of your sails - the result: much better 0-60 (i used to switch off the TC before if I was in a hurry) and much better to drive.
Anyone else noticed this?