Last year I went through about 6 months of phone calls, letters & emails regarding the Briggs engine in my Husqvarna (sp) 48". During that time I found that Briggs engines are about done in at 350 hours - at least the ones sold in the big-box store units. I'm praying the $950 replacement engine (bought at a local small engine shop) lasts longer than that.
Looking over one of the Snapper units at the local Wally World, it looks just like the Husqvarna except for the paint & decals. Same frame, steering, deck layout, controls, etc.
I mow around a *lot* of trees and bushes. Even with a 4' - 5' circle around some of them I end up backing and filling 3 to 5 times to get around them with the tractor type mower. If it weren't for a couple other reasons (towing, hills, etc.) I'd prefer a zero-turn. Actually, I'd still prefer a zero-turn. From what I understand, a zero-turn is also usually faster in the straightaways than a tractor type.