Anyone have any experience w motorized trailer dollies. My prob is that I have trouble backing my PUP (1500# dry weight) into the garage. We live on a narrow, sometimes busy road, have to back the pup over a berm, down a 20 degree slope for about 30 feet, into the garage where I have about 3 inches of clearance on each side. I haven't mastered backing yet but can move my PUP around by hand on flat ground, but would likely lose control on the slope. I have been considering one of these dollies to help me off load the camper at the street and slowly push down the hill. Do these things really work on hills? I saw some that are a couple hundred $ and some are a couple thousand. Any type work better than another?