The brake issue is overblown. Yes, some people have had problems, and there's a recall to correct the problem. The majority of owners have not had any problems, and it's still the best chassis out there. A buyer is probably going to be informed, and if you have addressed the issue it shouldn't be a problem. The values are in the tank because of the economy, and RV's in general are all selling for less. You're maybe talking five or 10 percent either way for the brakes. I would not sweat it. I sure wouldn't if I was selling mine, which I can't because I owe way too much on it and would have to buy my way out - OUCH!
Like my Duramax - the LB7 has a known injector issue. Most get replaced and GM extended the warranty to 200K or 7 years. Even so, as long as they run good they're the best darn trucks out there and resale is still strong. So even if you have to replace injectors on your nickel, a used one sells for less than half of a new one, so there's still value and buyers at that price point.
Toyotas have taken a hit, but people will still buy them, they're still great cars even if some have had problems. Unless you have a Lexus GX.