Flip-up camper doors vs Barn door halves

[Voyageur]

I'm working my way through different options on a pop up truck topper/camper. The one thing I can't make up my mind on is what kind of rear door to get. The traditional flip-up door comes standard with the camper whereas the barn door halves are $500 extra. I'm curious to hear from those of you who have had or have a topper with the barn door halves...likes/dislikes, advantages/disadvantages, etc.
Thanks.