lopakamac-- I have owned both a RT 210 and then a Trail-lite 251. Quality is unquestioned in the RT, mine did leak at the rear doors and the AC was so shrouded in the rear that it would shut itself off above 90 degrees. I sold mine because we camp mostly in the desert SouthWest and the RT,although beautiful to look at was an oven at night when the outside temps were above 90. I now have ducted Dometic 15K unit which will keep everything nice and cold on even the hottest days we have seen in the Mojave last May. No more sleepless nights fiddling with doors and window covers and the AC trying to make it through the night till we could get moving again and turn on the truck AC. Now I sleep better at night and the Trail-lite has no leaks. Mine has no slide-out, though, so I can't speak to slides. Still the RT is about 87" wide and the TL is 99, so everything is a full foot wider inside, and it makes a great difference. Oh yes, I don't bang my head occassionally in the TL like I did in the RT.