I have a Harbor Freight one-it's on its second set of covers now-the sun will eat the cover up in just about a year or two-I keep another big tarp over the new cover now, and this has protected the cover well (I also moved the garage into the shade at the rear of my yard,which has helped). The sun will also eat up the little bungee cords holding the cover onto the frame over time.
The framework just loosely fits together, which makes assembly awkward, so I used self-tapping screws to hold all the pieces together, making it much more rigid-just don't position the screws where the heads will wear on the cover.
The "garage" has held up well in some very strong winds (it has a tractor in it now, and the tires are parked on boards which are holding the side rails down).