I find a fifth wheel much more stable when towing that a TT, so I would not be overly concerned about that, though I have noticed some “surging” on concrete highways. I have been able to counter that with adjusting speed.
As far as backing goes, go to an abandoned—preferably—or empty parking lot and practice. Pull up further than you think and then back slowly. Do not be afraid to pull up to keep the truck straight with the 5er. You might also want to invest in a set of walkie talkies; they are easily worth the price you pay. A truck driver gave me the best advice, which was to take advantage of your mirrors. Since I started doing this, I have found backing much easier.
These Montanas truly loom large when you look up at them or when you hitch up, but they can be easily managed and I have found they behave well, unlike some animals and small children!
