I have a 2007 Keystone Outback 25RSS. The "RSS" apparently stands for rear and side slide, since mine has both. Bunks across the front area. I bought it used in 2011 and have never had any leak issues with the trailer at all. Not from the slides or from the main trailer body. It's been through some significant rainstorms while the rear slide was open, and has also been snowed on while open. No leaks at all.
No problems with heat/cold either. When warm the fan does a good job of stirring the air, and with the windows and rear door open, there's never been a problem with heat. Likewise, with cold, there's not been a problem. I replaced the standard mattress with a memory foam mattress, which seems to block out any cold from the bottom. The side walls are thin, but there's a heat vent directly below the slide out that provides sufficient heat to the slide.
The Outback also has a 50/50/50 tank system, for fresh/grey/black water. With judicious water use, I've been able to get 4 days out of this combo, could probably go 5 if I had to (usually carry a 5 gallon container for cooking/drinking water).
The rear slide is one with the queen mattress sideways, meaning that if 2 people are in it, the one closer to the window has to crawl over the other person to get out. Some of the models after 2007 had the head of the bed at the rear window, eliminating this problem. It's not a big problem, just that it's there. If I had to do it over again, I'd buy the same trailer, but with the change of the head of the bed. The rear slide is what attracted me to this trailer, since it gives a lot of living space when open.
