The whole suspension setup is completely different on the front due to having to accommodate a front axel
Compare these images from a 335
to the 335x
The front stabilizer bar on the X is a little beefier than even the sport (normal=21.2mm, sport=22.2mm, x=22.5mm) but they're really close
On the rear, all the components are identical except the rear stabilizer, the standard and X suspension share the same 12mm stabilizer, where the sport gets a 13mm bar.
On the front and back all 3 types get different shocks, bump stops, and springs - the X carries the same ride height as the standard suspension, the sport is 10mm lower. X has slightly heavier springs than standard to deal with the additional weight, sport springs are heavier and shorter.
The story's the same with M adaptive suspension, different shocks, bump stops and springs - the adaptive on RWD is 10mm lower than standard (same as sport), where the adaptive on X is same ride height as std.