it was fine and we used it a ton in the 2 summers I had it. I upsized to a larger tent on a different truck. but it was fine. There are a lot of mounting options so now days so it should be easier. Mounting is always a pain.
The one thing I would say about a clamshell (and the reason I did not go with one) is your competing with the rear hatch. when I'm camping I use the rear hatch all the time and it would just be a pain to deal with that and the ladder in your way all the time.
I ran a 55” tent (1.4m) for a few years and then moved up to a 63” (1.6m). The 1.6 just starts creeping over the sunroof, but not by much and it still functions fine.