I bought the the XR as the XRS 180 hp model is so high strung, not nearly enough torque at anything below the peak at 6,200 RPM. DO not quote me on this but it is my understanding the 180 motor has very high compression making presurized power not easy to achieve and maintian.
I am very satisfied with my Matrix XR (XRS body kit) stock for now, well not really, already at E.L Prototypes for some tweaks

Actually I am letting them, to both our benifit for sure, use mine to prototype intake, headers, turbo kit, etc.
For such a tall vehicle it handles remarkably as well. Will be lowered soon and more aggresive wheels, tires as well.