A big part of why I went with OVRLND and still love it, is the amount of customization they will do on order. You can really get something built to purpose, I've only seen Topo come close. I did Tern windows in my hatches, which along with my DIY insulation have been great for our winter usage, we just did 50/50 barn doors, but wouldn't do any cap style camper without barn doors now. In a long bed you can go single hatch, 2 hatches, hatch plus window, hatch opening up or opening down, and that's just one side. Fixed window, sliding window, terns, no windows, you name it OVRLND offers it and on any side.
With any of the cap style campers, being able to DIY the layout, or leave it open for use as a truck bed is a nice advantage. On the flip-side a slide-in can be nicely self-contained and easier to remove and store. I kept my Gladiator camping setup easy to remove so I can use the bed for truck things, and don't really notice the OVRLND when I'm angling down off of Moab ledges or bouncing around on our Montana rock trails. I only lost about 1-2mpg with my v6, I doubt a SD/HD truck would even notice it.
We're looking at a 2nd build with an F250, so have been contemplating similar questions.