I'll weigh in here. I have an 02 Winnebago Adventurer with the basement air. When both compressors are running, it pulls nearly the entire 30 amp service that I have. I've discovered that sometimes this will trip a weak breaker at the pole. It's something that I have to keep an eye on. Once the interior gets cooled down, it'll easily maintain about any temperature inside regardless of the temperature outside.
I don't mind the noise under the bed because the unit stays off most of the night when I'm asleep.
What hasn't been mentioned here, but what I find the most annoying about the basement unit is the noise it makes when I'm sitting outside under my awning. The condenser is on the passenger's side, right behind the awning, so sitting outside when it's running is a bit annoying. I wish Winnebago had put the condenser on the driver's side.
Other than those two items, I really like the basement air and the clean roof line that not having two roof units provides.
Tom