B@S engine I/C: is it really commercial quality? Garden tractors?

Briggs and Stratton engines are good if taken care of well. (regular oil changes, battery checked, air filter changed or cleaned, external engine cleaned, with clean fuel). Chances are the tractor or mower deck will fail before the engine. I have an older MTD that has seen some rough service and the engine has never given me any problems. I've replaced a lot of belts, blades, mower deck parts, and tractor steering parts)