The Ariens Pro 21 is extremely well-built (in the USA!) with a high-quality Kawasaki engine. Mulching feature works so well I never bother to use the bag. The only disadvantage is that it is so well constructed of thick gauge steel that it weighs 100 lbs! Fortunately, the self-propelled rear wheels work well and make it easier to turn than the the front-drive models of mower. I spent considerable time searching for a well-made mower and am convinced this is one of the best.
This mower is undoubtedly a commercial product. It is very well constructed, and has a strong engine. However it is very heavy, 120 lbs., and as such is hard to manuever without engaging the drive. It has a great cut, starts right up, and runs smooth. The only problem I've encountered is a tendancy to stall when on an incline. I hope after I research this I will find a simple solution. I got free shipping with this item, and it was trucked right to my garage, a nice plus.
The self propelled mower worked 3 times and then would not start. We tried everything and we were finally told that you need to use a mid. or high grade gas. If this is the case it should be indicated in the manual.