i have the sts d28 5 port in a xtm mammoth st 10.5 lbs. my brother has a jammin jpx 28 in a jammin x1crt 9.5 lbs. my dad has a rex 528x race in a jammin x1crt 9.5 lbs. my sts 28 smokes the jammin and rex from the start to finish. we race in a parking lot with a big strtch and the sts beats them every time no bull.for the money sts rocks.i would have to say sts is one of the best if not the bgest 28. sts slso has the new s28 thats even better so whatch out .