How short and how often do you want to cut ten acres? If you use the zero turn, then you need to be cutting it once a week or it will get too tall and you won't be able to cut it. If you want to cut once or twice a month, get the tractor. If you don't mind it getting a little thick or tall, go with the tractor. If you ground isn't nice and smooth, go with the tractor. If you are in a hurry and you can afford more HP, and then a bigger mower, go with the tractor.
Ten acres is quite a bit of land to mow. Especially if you want it t be manicured. I do a few acres with my zero turn, and it does an amazing job, but if I miss a week, then it's a nightmare to get through it again with the zero turn.
Eddie