We have the same set up as Over the Hill describes. We really love it for eventing trials as we pack hay, water, saddles everything else and it stays dry and out of the wind/weather/eyesight. Leaves a lot more room in the trailer dressing room as a result.
We fold it away for haying season; it has cross bars so it keeps the bed snow and rain proof.
Like Jim we had a “rollup” cover and it worked reasonably well for several years. But then it started to develop problems and within a few months went from useful to being removed and scrapped. We kept it lubed IAW manual directions but it was likely too lightly built and just wore out. We did replace the retracting spring once (3 years after we put it on?). That was failing when we pulled it but was still working.
Since that time I’ve tried to put on flatbeds where possible. They are vastly more useful on both farm and towing trucks.
G.
I have a snap on cover. As was said, in cold weather it is difficult to re-snap, and with this style there is no way to lock the tailgate. So, I can’t store anything valuable in the bed.