Welcome, I'm also a fly fisherman, along with a bunch else.
Our Eagle has been through 50+ mph winds while setting high on the jacks, no truck holding it down, with no problems. I did worry a little and out in the darkness and rain did go and lower the jacks some, but it was not moving at all. The top was up and had no problems. It's been through some pretty good winds while on the truck too crossing the US. Years ago I had a Toyota Chinook which was also a pop up, with not as strong a fabric. It went through up to 80 mph up in the Northwet in the many years I used it with no problems with the fabric up. I'm sure it's possible to find enough wind somewhere to be a problem, but as someone else said, less likely to rip the fabric out than have the rig blown over. And neither seems to be something people experience.
Somewhat you do want to decide on what equipment you want onboard. There are a number of sizes of FWC campers, and it's harder to put as much in the smaller ones compared to the larger ones. The camper is a package of equipment packed in limited space, so has to be planned to enjoy. It's all about using space and keeping the weight reasonable.
My Eagle I bought used, it had no need of any repairs, was in excellent shape, is a 2007 shell model. Buying a shell model is like buying a blank slate as to what it will become. The original owner only added a bed shelf all across the lower camper, no appliances except the standard lights and a fantastic fan. He had several kids who used the lower bed area and he and his wife the upper. Eventually they outgrew the Eagle. It did have the optional sliding front window, Yakima rack rails, a set of mechanical jacks, and the fantastic vent fan added to the basics for a shell. That sliding front window is actually a critical thing to have already on the camper, it would be tough to add one later. With it you have the ability to send warm and cold air into the camper from the cab as needed when traveling. I got the boot for mine to seal that opening and the windows are always open and connected in mine. As mine is a shell, and shells don't have the frame much designed to fit the appliances it's a challenge to work on to do what I want.
I've already replaced the rear door in order to add a screen door. I'm in the process of adding propane system, water tank and pump, 200 amp hours of house battery bank and electric distribution for same, hookups for charging those from the Ranger it's going to be used on. 110 volt connections and battery charging from that as well the few times it will be available. 12v/110v Compressor fridge, 2 burner cooktop, Propex heater, outside shower with tankless hot water heat, microwave (which will have a big inverter to power it for the short intervals needed). While trying to preserve enough lower bed so my wife and I can have a choice of sleeping up or down together. I will be putting in the lift struts as I'm old enough to need the help lifting the top. Later I'll add solar charging, but at first primarily depend on the Ranger to keep the house batteries charged. Will be adding more outside LED lights spotlight and good light for backing up out in the bush at night. I've already changed all the Eagle's lights over to LED to cut power usage. We will primarily be using the Eagle for photographic forays and such custom for what we want. It's quite a challenge to fit all that into the Eagle and it will not be using the standard appliances for most of it. We do not expect to be where there is a regular campground very often, we tend to vanish away from people. A bigger camper would allow fitting easier, but would not fit through the narrow back roads we so frequently are on. Even with the Eagle some places we go into now will be written off.
So, think through just what your ideal stuff will be in the camper. Then when you do find campers to look at you can make a better judgement as to what value to you the camper you are looking at has. Appliances can be a major portion of the total cost. Don't be surprised to have to drive a fair ways to look at one and buy it. And be ready to do that in a hurry, they tend to sell quick. I drove from Georgia to California to get mine. Though having to drive that far is more than usual. The eastern US does not have a lot of these campers, much easier to find in the west. I camped in mine for over a week before even getting home with it.
It's an adventure in itself trying to find a used one, or deciding on what to put in a new one if you have deep enough pockets. Even before you get to use it. It took me the better part of two years to find mine. Now I'm just pushing hard to get it all ready for use, there are still wildflowers out there, and the winter frogs are starting to call.
