With the tight confines at the house, we're looking at the "Park It 360" Force 10 B2. The drive's about a 2-3% grade. Does anyone have experience with one and/or the company?
I got this 7 years ago from a company called Power Mover (they're out of business now) for about $1200 shipped. Works great, but I don't have any grade:
And it's the only way I can get both the boat and camper in the backyard: