We too have a slider hitch in our short bed but have not had to use it. We were in some pretty hairy situations and I think my husband forgot we had it LOL. It's a nice thing to have just in case.......
As far as your tow vehicle and Montana combination, I'm not sure if you are going to have any problems. They don't have the specs for that unit on the Montana site any longer but I'm guessing it's around 10,500# dry weight (at least). You don't say which V10 you have, you could pull anywhere from 10,200# up to 13,200# depending on which engine you have.
Good luck and congrats on your decision.
