Hiya,
Power equipment from the big box stores are on sale there for one primary reason, price point. The large retailers negotiate with the manufactures to "customize" the product line so that the price will be more attractive than the other big box store around the corner.
The term "customize" in the large retail world is a misnomer, it doesn't mean a better product, in almost all cases it means a product with a bigger cup holder, fancier decals and one that the engineers were asked "where can we remove costs without effecting reliability during the guarantee period?"
The big box stores do not care about after sales service, they don't honor warranties, they rely on the individual component manufactures to handle claims. The component manufactures have also learned that price is king in the big box world, they have lowered the quality of the components and "gamble" that the equipment won't be used hard as most people that buy PE at Homer D's or Low's are simply "keeping up with the guy next door" and use a rider to cut a 12x35 foot lawn not 3 acres and they aren't looking to spend a lot more $ on equipment that has commercial engines like Kohler, Kawasaki or Robyn that will last 40 years because by then, the paint would be faded.
The "new" B&S engines have been separated into several classes, in order to get something on par with the other commercial duty stuff, you need to go to the very high end of the B&S line, far away from the "value line" offered for big box equipment.
The best example of the quality difference between big box and real commercial equipment was me and the guy next door about 20 years ago when I lived in the 'burbs, we both bought new 21" self propel mowers the same week, He got one from HD with a B&S, I bought a Snapper commercial with a Wisconson/Robyn. He paid $250, I paid $750. He cut his 1/12th acre lawn, I cut mine, my mothers, my aunts and the older couples around the corner. His lasted 3 years, I still have mine and so far the only things I have had to replace are oil, belts and blades.
OK,my soapbox has been put away,
Tom