There is not a comment above that I disagree with and there are good reasons for either style.
My wife loves her side entry WBBB. My go to hammock is a HH Expl UL with a 2QZQ zipper and slit still functional. I also love the simple, netting free top loaders. Yep, personal preference is the biggie.
The best recommendation would be to go to a group hang, like the one coming up at Cado Lake State Park in North East Texas, and try several to see what you like.
Another option is to find hangers closer to home and sample before you buy.