I've been looking around, and I think that I've partially answered my own ?
Kohler has several lines of engines. Some homeowner, some commercial.
The homeowner line is the Courage. These are known to be hand grenades. They have the worst set up for bearings [plain or none as the case is cut to have rotating part turn in the case]. These should be expected to last for 2-5 years of light duty use. Generally accepted that these should be kept away from, unless you like headaches.
The Kohler line to look for is the Command.
B&S have a few more slots in their line, with varying degrees of durability. I've not heard about "commercial turf", pro this and pro that. Inteks are B&S's version of the Courage.
The best to look for [to keep it simple] is the Vanguard.
Kawasaki and Honda are much less confusing [but also more expensive]. Most of both of these are good, Honda has a cheaper consumer engine [plain bearings...], but that'll probably be much better than either of the K or B&S consumer engines.
Kohler=Command. B&S=Vanguard. Any Kawasaki. Most any Honda [except the GC ?].
This is the way that I've come to understand what to look for and what to stay away from.
Any help or clarification?