As already said make sure you have a method to manually retract a slide when it fails, and they all fail, except for the guy with the 20-yr old motorhome, so maybe not. And don't take the seller's word, ask for a demonstration.
I've had multiple slide failures, fortunately each time the slide was in as it's a PITA to retract manually, so we were not stuck in an RV park waiting for a tech.
Also, on our old Class A we had the occasional soaked carpet due to the rear slide. Caused by 'special' rain that poured off the rear of the slide-out cover and down the seals, and these were newer, 2-yrs old, and well maintained seals.