I would say the difference is only in the movement. Both looks to have the same case, bracelet, etc.
Perhaps you are referring to which model offers the best bang for your bucks. I would have picked UPO with asian clone of ETA movement. Some kind like what daytona4me is selling through group buy
Get it, you won't be disappointed if you have the wrist size to tackle this watch. This is not a small watch. It wears bigger than most 44mm Panerai.