I have a 7000# 18' Dove tail trailer. Works great. I got a great deal on it used from a friend of a friend a few years ago. If I was ordering a trailer new, I might have went with the beefier axles. It is not that much more when buying new.
I have not had any problems pulling it with our motorhome, or my old F250.
One thing I love about the dovetail is that it is easier to load a regular non-lifted vehicle on it. I never have to pull out the ramps to load my Jeep. My friends get more use out of the ramps when they want to borrow it to haul their broken down piles. One of the downsides to owning a car hauler, everyone wants to borrow it.