Well. I'll tell you, from experience.
I have owned an LM21SW for more than six years, as a professional yard and lawn maintenance company. I am not easy on my mowers, and this one has held up very well through daily use.
The Kawasaki 6HP motor has plenty of power, and the bagging capabilities are great..
Ten seconds on the delete key.....
But, the castered front wheels, how well do these work for you?
IMO, a great idea, but Ariens seems to be the only one in the arena of walk behinds.