We had a 23' Thor Gemini with a rear slide. We don't have it now as the space inside was barely adequate and the bath was essentially an airline bathroom with a shower. Not too good for anyone over 6' and 200lbs. You had to be really careful using that bathroom sink.
The great thing about the rear slide was the ability to park anywhere a 26' could park. No problems at Wally World or Flying J or Cracker Barrel. Basically, just a big station wagon.
The bad thing about the rear slide was the height of the bed when folded down. About a foot higher than a 'regular' bed in a slide. It's probably ok for some younger person, but us older folks found it problematic after a while. It really didn't open up the RV when it was out.
We went with a no slide with rear queen walkaround. MUCH better. Got to pick our spots a little more, but we can still get into gas stations and the aforementioned over night spots with no concerns.