We just set ours up for the first time....
A couple of things to be aware.... They are heavy in terms of transport.
Easy to put up... Took us maybe 15 minutes and that was the first time., but I would not use it for a one night stay, too much packing and folding to put away, but great if you are staying somewhere for several days.
They definitely increase your space....and if you are in a part of the world where there are lots of bugs they are great. Also I find it works great for a place to leave shoes etc. And have them stay dry. What I like best about it, is that the side panels can be rolled down to create shade and privacy, thus allowing you to be outside truly all day and even if it is raining. I even packed a foldable chaise lounge for ours which has become my favorite place to be when camping.
However... They are not totally a perfect fit... There are openings along Where the screen room meets the trailer... You would need to pick up some long foam edging to stick in there to make it completely tight. The stuff that insulates pipes would work, you can get it at home depot.
Also pick up some silicone spray to put into the track before you insert the first panel. It also works well on sticky zippers.
I would buy the largest one you can get for your camper... If you are going to do it, then go for it.
2003 21 ft Forrest River Shamrock