The Quest unit is my biggest gripe about the amenities in our Montana. We have a Quest 1000 and the bass is overpowering. I have attempted to adjust this properly, but even with the bass at a setting of 1 (lowest is 0 which is off), we get the heavy thumping.
Also, since the last day of the national rally, our quest unit started to require a password for every DVD, but we never enabled Parental Controls!
I'm not going to say that I'm an expert on home theater, but I have a good system in our stick house and I grew up with different home theater setups. So, I know my way around these things and the Quest is the worst unit I have ever seen.
We're looking at either a Panasonic or Toshiba replacement Home Theater In a Box. They both cost around $300, but have good reviews online and are made by reputable brands (Believe it or not, Panasonic and Toshiba have websites and online support...Where is Quest online?). Even if we wanted to go cheaper, we can get a low end Koss or Audiovox setup, with speakers for around $170...and that's in Sears!
Anyway, we have a couple of months before the weather clears up enough to really do any meaningful work in the RV, so I'll be shopping around for the best deal on either of the two brands. I recommend keeping an eye on Slickdeals.net, they have a very active site with deals, usually 4-5 pages of posts per day in their forums.