I can't say I'm an expert and the one thing that is constant is change. But from those that I've seen they are all about the same more or less. You will find some with more weight support making it easier to open and close. Keeping them clean and lubed is about all the maintenance I ever did. Rolling ATVs in and out would get a lot of dirt, mud, sand so I made sure to wash them down.
I can't say our door was better or worse then our garage - it was always cold and that era didn't have heaters or an outlet in the garage either.
IMHO they are all about the same, look for weight ratings of the ramp itself as well as the garage. If buying new and it's not posted I'd get it, in writing, from the manufacturer. I wouldn't say it's going to be better made if it's also a deck though, the attachment points are the key in that aspect.
Most all use a padlock or the "puck" style padlocks for cargo trailers. I've also seen a few people setup interior locking mechanisms too.