If you have any slopes beware of the zero turn mowers. They do not do banks very well. They will pull the front of the mower down hill if you are going across the hill. They tend to pull out of control downhill. They do very well going up hill and backing back down(kind of scary though). I bought a 26HP 60 inch cut commericial machine and had it a week and took it back for the above reason.
I went with a used (100 hours) BX1500 with a 54" MMM and I am very satisfied with the way it works for my situation. If you are mowing level ground the zero turns are great but not on slopes. So it would depend on what you are mowing, but for me the BX machine fit the bill.