We have had a Fleetwood cobalt for around 6 years now. It has been a really good fit for us. Great for 4 people. 5 is acceptable for sure, but with the 5th we have decided to upsize a bit. I think the key with pop ups is going in with reasonable expectations, and then you will enjoy them. I originally had intended to upgrade suspension and tire size, but after using it never felt that was needed. Great for forest service roads and rough roads/ two tracks. The wheelbase is short and the lowest point on the frame/suspension is decent in stock form (no pumpkin or shock mounts hanging low like a vehicle would have). I routinely air the tires down when on rugged terrain. In stock form, the trailer will go 10x farther than a standard camper or fifth wheel, which opens up the camping possibilities in the west tremendously, and offer more secluded camping. In stock form I would not take it on truly rated jeep trails, but long rugged tracks have been not problem for us. Screws have needed to be tightened and some rivets replaced though on long rough tracks. On our particular trailer, the roof is aluminum and is not susceptible to UV damage like some late 2000's Colemans, but one may have to reseal the edge sealant if it is dry and cracked. we have never had any leaks with ours, but if improperly cared for leaks can ravage a pup up. Also be wary of campers with a roof AC unit as that can be a place for water to get in and can create weak points in the roof. Deploy time is decent, but the down side is that many of the storage areas (under the bench seats and table area) can only be accessed when popped up, so packing and returning home from a trip you have to be a bit deliberate in your packing in order to reach items without doing a set up. Ours also came with a rack on top so we routinely carry an kayak up there.
Used pop up camper shopping can be painful as you have all of the typical RV problems but also lift mechanisms, bunk slides, and canvas to worry about, so do your due diligence when shopping around. The nice thing about the cobalt is there is only a 5 gallon removable tank with hand pump handle, so there is not a water system or winterizing to worry about. It came factory with trailer brakes, which was a perk when pulling with our Cherokee.
Another note is we live in bear country, so all food is stored in the vehicle, and cooking is done outside away from the canvas. We do eat inside in inclement weather.
Overall, pop ups are not a mass appeal kind of trailer. For the RV crowd, they offer less security/noise dampening when in a more populated setting and are overall less convenient. for the expedition crowd gone weeks or months at a time they do not offer the ruggedness or durability needed for extended offroad travel. But for those of us in between that are weekend warriors or week long trips into remote places they can be a good fit. We recently upgraded to a larger camper and were looking at the more offroad marketed travel trailer, but came full circle with a larger pop up with a small toy deck on the front.