I use the rail mount Andersen in my short bed Ram and it does great. It doesn't make contact at full lock going forward and I can crank it as far as I need to and then some backing up without making contact, and I've played with it quite a bit since I got the setup. My fifth wheel has a square style front on it too, and I bet with a newer style front end you would have no issues at all.
I love my Andersen hitch. It's totally smooth and solid with zero clunking or movement, and it's lightweight and very easy to install and remove. I prefer the way gooseneck style hitches perform and the Andersen is a great way to get that without the drawbacks that can come with the adapters.