In my opinion, if you need greater than 3/4 HP for residential use you may be using the disposal as a garbage can instead of it's intended use.
"Keep in mind that a garbage disposal/food waste grinder is not designed or intended to be a food receptacle. Food and waste is still supposed to be scraped off in the garbage and the disposal is supposed to take care of the parts that don't make it in the trash. There is a long list of things that should not go into the disposal and the manufacturers may advise you on the warranty card (coffee grounds, egg shells, rice, etc.)."
I have an old 1/2 HP ISE disposal that my wife acquired used. At first she was peeling potatoes and carrots into it and scraping full plates of food that would jam it up. In turn, the stuff that did make it through was causing build-up in the drains because it just didn't belong there anyways. Once I educated her on the proper use of the disposal we have been trouble free for 4 years and the disposal still runs like a champ.
A builder that I worked for installed only WasteKings in his homes because of the lower price, but I had more service calls for them than ISEs that were installed for another builder. It seemed that WKs would need to be retightened from vibrating loose and leaking, would leak from internal seals and jammed up easily. On testing the appliance after a new installation in a new construction home, I have returned WKs because of defects or performance issues, but never had to return an InSinkErator. Some customers would ask for and pay for a replacement and seemed more satisfied with the ISE Compact upgrade.
I'm trying to be objective so that you can form your own opinion. I wouldn't want to be accused of badmouthing a product that others may be very satisfied with.