The XtraRad feels and rides way better than the stock Unilli (switched at 400km). XtraRad carves better and grips better. The softer material also absorb shocks and bumps way better.
I used to have speed wobbles while carving on stock. It was insanely difficult trying to balance/carve while riding on grass and packed gravel/dirt. The board would feel like it has no grip and wants to slip out. But after installing XtraRad, the speed wobbles are gone, I can carve better, manuver better, and better control of the board. I can now ride streets, trails, packed gravel, and grass no problem.
Nothing bad with stock if you just ride street but it's not the most optimal. But the ride experience will be night and day on the XtraRad compared to stock. Highly recommend XtraRad!