I've got an H+H trailer for my race car. It's 24' plus a 2' V nose. I opted for the flat roof, the trailer was unfinished when I bought it. I've since painted the walls, done an epoxy floor and wired in AC power. When we're at the racetrack, we kick the car outside and sleep in the trailer.
My only complaint is they used scotch locks on every connection for the lights. I had to re-do every one of them the first time I used the trailer. They had also installed the lights tight enough to actually crack the housings. Command Electronics was kind enough to warranty every light on the trailer when I ordered the replacements.
Other than that, it's been excellent. However, I wash it every time I use it and store it inside. It's never seen snow/salt.