I think one of the key things to look for is a steel piston with a cast linner,you want a solid investment.I would bet my bottom dollar the Ariens would be the best for your money.
Mines a 19 year old a Craftsmen 8.5Hp.26" cut & 11" impellar my Dad owned it for 17yrs & since he moved I now own it,ten yrs ago the carb had some problems and the chains keep comming off so I took them off other than that I love it.
Paul I to store mine in da shed I forgot to put moth balls in it & apparently one nested in around the muffler,I found out after I fired it up & I can smell the Chit burning and also smell Ammoinia
Bob