Yeah - usage with slides in must be taken into account. It depends on how you use your trailer too. Some people never stop during travel or don't travel far enough need to. Others eat on the side of the road or in a parking lot daily.
I really like the rear kitchens for livability but a "must" for me is to be able to funnel dishes onto a counter from outside after outside meals. I'd go crazy if I had to walk up my stairs and across my trailer to get to the sink. The mid-kitchen island trailers are little better I suppose but I have never had one. Every trailer I've owned has the counter and sink right inside the door.
Most of my complaints about interior stuff are size related. At 6'4" I've finally accepted that RVs just aren't built for me. Showering with my head in a globe (skylight) is just a way of life while camping, I suppose.
I think the biggest way to know what you want is to own trailers and learn what you don't want. Personal habits vary a lot so what you need a trailer to do will as well.
