The MPC One is the entry level, the price is a bargain, they had to save on everything.
The MPC Live II has more features and costs more.
They had to make choices.
I made these considerations when I bought the Live II: internal battery, internal SSD, internal speaker, bigger pads, more outputs, phono input, better connectivity (USB data access, wifi, etc). Add all those things to the One and you are not far from the price of the live II.
With the Live II you can stop worrying about hardware limitations and just start complaining about the software
Buy once, cry once, you know!