I'm also debating on which side to go with. This sounds super lame, but I don't want to obstruct my Pro-4x badge on the rear hatch, so maybe I'll go drivers side.
That's not lame at all. Another thing to consider is whether or not it obstructs your rear view camera. There is a reason Gobi makes both sides.
I'm personally running a passenger side ladder, but it was just a visual preference for me. I also thought I MIGHT want to add a tire carrier back to my bumper one day (had one before, didn't like it, but things change), so at least the ladder is in the correct place already. Plus, if I ever decide to pull it off and sell it, there is a larger potential market for the passenger side since it'll work with a lot of people's tire carrier bumpers.
Either way, you can't go wrong. It'll look nice and work great!