the X is a larger 50" version with incredible power to weight and only about 8oz per sf wing loading.
They are both incredibly easy for first time 3d pilots and many of my friends never hovered a real plane until they flew my X for the first time. Advanced 3d, ground is the limit; check out some of these videos as they really showcase the PA planes very well and are some of the highest quality RC videos on the market IMO:
just start at the top and work your way down.... I may have ruined your productivity for the next few days