A couple of years ago, I picked up a used cement mixer at a yard sale for $5. It was in good physical shape but the electric motor was missing. I installed a hydraulic motor, welded a SSQA plate to the legs of the mixer and used the 3rd function valve to power the hydraulic motor. I use the tractor & FEL to mix, transport and dump concrete wherever it's needed.
I like that I no longer have to set up the mixer next to the sand & gravel piles and cement bags. Instead of bringing the ingredients to the mixer, I now take the mixer to the ingredients which are usually stored in different locations.