I prefer the bakflip f1. When I've hauled big stuff, if it was tall, I only needed 2 of the 3 panels open, which is still flat with the bed. In a year I haven't had to flip all 3 open and block the back window, but really if it's something that big, the object is blocking the back window anyway, so what's the big deal if the cover is blocking it lol. With a backup camera and huge sideview mirrors, it's really a non-issue for me.