Well I went ahead and got the revo stage one anyway. If anybody is contemplating whether or not to go for one, all I can say is it is the best spent money you can spend on your tdi. The revo map absolutely transformed the car.
I didn't get it on a rolling road so I don't know actual figures but I don't really care about the numbers as it feels so good.
I've had other cars mapped in the past and the revo feels the best of them. Smooth linear power delivery with no lumps anywhere in the rev range.