Those saying "Improved my driving" just means that the buggy you switched to fits your drive style better than the previous one, not meaning that either buggy is better than the other.
I have never raced a losi but been racing the X6 for about 18 month and have not looked back. The only thing I have replaced in 18 months in my X6 is the chassis about 1 month ago. Slop is minimal, Mugen's plastic holds up pretty good.