What’s the difference between B1X & B10 Plus?

Answer 1: The B1X is a more robust and has a higher battery capacity. The B10 Plus weighs less, has a continuous light and Bluetooth-connectivity. 

Answer 2:  Power output isn't the only important factor in a flash and the B1X and B10 Plus differs on many such topics. For example, the battery capacity of the B1X is higher than that of the B10 Plus while the B10 Plus has the continuous light feature (not to confuse with modelling light). Please check them out on Profoto.com for a more complete picture.