Seems to me there would be problems asssociated with slide outs. I can't anticipate what exactly all the problems might be ... but more slides mean more moving parts and more things that can go wrong. (What are the actual problems? Rain leaks? Crooked mechanisms, so that the slide is impossible to slide?) Do they also have a downside when they are "in" rather than "out"?Some slideouts are a bit under-engineered, and being on uneven ground can twist the frame of the rig slightly making the slideout motors work a lot harder and several other parts wear out faster. So it's important to have the rig level and stabilized (with the jacks) when working the slideouts. Also, before buying a rig, get online and look for comments and service bulletins about the candidate rig's slideout motors. Check dates; sometimes a given model will have problems with the slideout motor (or any other specific problem) only for rigs made in a certain date range.There's typically an awning, with one edge firmly attached to the top of the slideout and the opposite edge equally firmly attached to the body of the rig just above the slideout. It works automatically with the slideout. However, a small amount of water (and leaves and stuff) can get under it, on top of the extended slideout, and be brought inside when the slideout is retracted. The awning fabric will need the same care as for any of the other awnings, and the less-complex mechanism (just a winder, no latches, no pull-cords, no hinged support arms) will need less.If the slideout is fully extended, it has a good seal all the way around (which may need serviced occasionally). If it's fully retracted, it also has a good seal (ditto). If it's somewhere in between - typically not.I've seen rigs where I really wondered if one could go from the cockpit to the bathroom while the slideouts are retracted. Without breaking through walls or climbing over the kitchen counter or dinette. I consider that an important question.Aside from that, the only problem with a slideout when it's retracted involve the slideout's front and back walls which wouldn't be needed if you didn't have a slideout (and may not cause a problem at all), and design decisions that would have been made differently if there were no slideout. For example, if there's a bedroom slideout then typically the head of the bed is in it, and opposite the foot of the bed there's a closet or counter with drawers underneath - and when the slideout is retracted you can't open most of the drawers because the bed is in the way. (So make sure you have at least one set of clean socks & underwear somewhere else.) With no bedroom slideout the head of the bed usually is to the rear of the coach and while you probably have less storage in the bedroom, all of it is accessible all the time.As for what can go in a slideout, the cockpit is of course never in a slideout but any other part of the interior can be. The least-common things to have in a slideout are the toilet and the entry door/stairway, but both do happen. The most-common things are probably the dinette and part of the living room, and the head of the bed if there's a bedroom slideout. Basement storage under a slideout can be part of the main body and awkward to access with the slideout extended, or part of the slideout and you need to make sure nothing gets between it and the main body while the slideout is extended. The latter may be handled by the design of the rig.Our one slideout includes the kitchen (not the refrigerator) and the sofa. The rear wall - which holds most of our food-storage area and is directly behind the sink - parallels the front wall of the bathroom creating a mostly-dead space from floor to ceiling, nearly 3 feet deep, and 3 inches across the open face. (We store a flyswatter there, and the oven rack when it can't be in the oven.) The front wall is directly behind the driver's seat when the slideout is retracted, but not a problem.