My 2 cents: Get a mower with a floating front axle (pivoted in the center); my son bought a ZTR at a box store this summer and he has since gotten it stuck when one front wheel would fall into a rut/hole and the opposite drive wheel would lift off the ground. My old ZTR with a pivoting axle never did this. Also, I would go with the higher HP engine and higher rated transaxle (check drive unit model on HydroGear web site); they are likely to last longer.