Once you have the diff set right you will see a HUGE increase in performance... I was having the same prob as you but now I've got the diff to a decent setting the car is very very responsive. I still ahve my slipper really quite tight, but I love wheel spin and instant power
I was for a while considering replacing my X-Pro with the new Cougar SV from Schumachar but now I have learned the correct settings I'll stick with my Ansmann for 2wd
... I'm a happy chappy.
The X-Pro has been a great learning tool. I've been out of the RC scene for 20 years and so much has changed, I'm so glad I got this car, I've learned a lot about set up and car variations for different conditions..it's been outstanding.
J