In my experience, having the swivel model matters a ton! I have a non-swivel that I don't use anymore because even in "flat" country, it's not really flat. The swivel allows for easier compensation when setting up on uneven terrain.
I use the Caldwell pivoting 13-20(something) it is a little high to shoot straight prone unless you are on a downhill so I just use my backpack if that is the shooting option
I have been using the Harris 25S model. It’s short enough to be able to use prone but tall enough to use from a sitting position. The swivel feature is a requirement for me.