I just bought one of the "similar devices" today... A Tow Tuff RTF-1500, rated for 1500 lb tongue weight
, 5000 lb trailer weight. I'm unimpressed...
I hooked it up to my light
weight tent trailer (1100 lbs dry, maybe 150 lbs tongue weight).
First, I don't see how it could handle 1500 lb tongue weight. The main unit is strong enough, but the height adjuster has too much play in it, and the locking pin doesn't seat well enough so as the adjuster flexes the pin works its way out. I don't know, but I feel if I used this on a trailer with significantly more tongue weight, it would fail altogether.
Second, it won't do what I need. I have a gravel drive way with very little (if any) slope. But the drive wheels are too small and hard -- they don't move the trailer, just dig into the gravel. It might work better on pavement, but how often do you have pavement in a campground?
So, it's probably going to be returned next weekend.