In my opinion the 12' mast is a waste of money and even a bit of a liability as it cant fit through an 8' doorway and will easily snag on overhanging tree limbs and such (the load clamp makes that situation even worse). In almost every loading scenario it is easier to lift multiple pallets since you are nowhere near the lift capacity. I have an older machine with the tall mast and the few times I have used it at the top of its height capacity I have found it is quite difficult to do it gracefully because every movement is magnified at that height. I use the 42" forks but a good case could be made for the 48" forks in many situations.
"Ve are too soon olt und too late schmart."- A nameless German philosopher