im not exactly sure wich one would be best, but the 4200 will give you just over 30,000 rpms (unloaded) on 6 cells and just over 40,000 on 8 cells...the 5300 will give you around 38,000 rpms on 6 cells and just over 50,000rpms on 8 cells..(all of these rpms are unloaded rpms)...ive never set up a rigger before, and im not sure weither motor will work better...but my guess would be the 4200....as the rpms arent too outrageous on 8 cells, but like i said, i never set up a rigger so i dont know wich would be better (more rpm or more torque)

edit (ryan, are you watching the threads im viewing so you can always post just before i do?)[&:]