I went out in a bluefin GTI last night actually for the first time. Compared with my Revo stage 2, it was a very smooth power delivery. It didn't quite feel as quick as mine, but not too far off.
My boost comes in all at once, and unless the road is bone dry and the tyres have enough temperature the car has zero traction in 1st, 2nd and a little bit of 3rd.