You are over analyzing. Either engine will serve you very well with reasonable care which is outlined in the owner's manual. Most manufacturers do not publish horse power figures because they are largely meaningless.Will 6.75 hp vs 6.5 hp really affect mowing performance and quality of life? I doubt if you would notice any appreciable difference. The things to watch out for are comfortable handle height, ease of operation and quality of cut. Do you plan to perform regular maintenance and keep a mower that gives a superior cut for many years ? If so, step up to a higher end unit such as Toro's SR or Honda HRX. If budget is more of a concern, the C/C will serve you well. Just stay away from the Chinese engines, service is a joke.

Just looking at the 10662, I don't understand why it exists. The 10684 seems to be pretty much the same except it has the ergonomic handle and bail, which I can assure you is the much better choice. They both have Tecumseh engines and 'Variable Speed' drive, which is my favorite. I've been using a 10684 for several years with no complaints. The Tecumseh engine has plenty of power and starts on the first pull.

If you can keep it up and running w/ carb spray, you are likely looking at an issue in the main jet which is in the center stem of the carb and must be removed to clean many times, or you can try repeated bursts with the straw of the carb cleaner. These carbs are pricey enough from MTD. Honda carbs are cheap, dunno if it is the same if you were to match yours up at a Honda dealer.

Well, i'd jump thru hoops tp buy the older Wheel-horse! That cub will never be the tractor the WH is. Somewhere, way back in time, the Cub was a good machine, but all i hear now about them is that they are just another MTD type machine, and they are going by the name, and their past prestige. I have a Model 1015. It still runs well, altho the mower deck is not in good shape, but you would have to know the people who had it before me to understand about the deck. Lack of care, and poor maintenance is the main problem. I was given a Toro-Wheel horse around five years ago. Didn't really need it, so i sold it to a neighbor. Last summer, he told me to take it home, so i did. And sold it again. Then i was given another one, which i fixed up, and now i use it around here for a cart hauler, and occasional mowing. The tractor is at least 15 years old, maybe more. Some of the recent CC's haven't been holding up very well-so think about it!