I have looked at both units for the past 3 - 4 months. The CK is larger and on weighs more. looking at both units you can see where the weight comes from. The tires , at least the R4's are larger on the CK and have a larger foot print (rubber contact). The bucket on the 302 B7500 is deeper and looks like it will hold slightly more then the 120 fel on the CK. he CK can raise its bucket higher and the roll back is greater. I have driven both on pavemet and the CK went in and out of gear, 4x4, high - low, with ease. The B7500 took a few tries and jugging the go pedal. Both units I tested were Hydro's. the CK seemed to idle much smoother then the B7500 even after reaching operating temps.
In a nut shell the B7500 is slightly smaller and lighter.