I recently installed a Coleman Mach 8. It was the lowest profile unit I could find. I have only run it a few times, mostly for testing, so I can't say anything about its reliability. It is not exceptionally noisy, but I find it hard to imagine a rooftop A/C unit that is quiet. IMO, if you have to sleep with the A/C on, it is best to avoid quiet campgrounds and accept the sounds as white noise. A larger diameter fan will generally be quieter than a smaller fan and this A/C has about as big of a fan as can fit in the form factor.