Mine has a mast, I do not have a crazy wheel, but would very much like one. I just haven't had a chance to build one. Eli mendez makes them, but by the time freight to the west coast is included it would cost more than my whole machine (again, ancient).
My mast does not have side shift. In general it is not a problem because with a skid steer you can kind of walk the forks against the sides of a pallet and scoot them over.
The main drawbacks are solved with the addition of a crazy wheel (swivel, castor, 5th wheel...). Without, you can turn pretty tightly, but to really turn sharp you jerk all over the place and/or tear up the ground. With a crazy wheel, they are really smooth.
I have 4 610 bobcats with mast and tail wheel and one s130 with mast and tail wheel. We are happy with this setup. They are dedicated bee machines. 3 have Edwards masts and the other 2 are factory masts.