Been pulling 36 ft to 40 ft 5ers with a long bed crewcab dually for almost 20 years. Been fulltime with the signature rig for over 8 years and all over the lower 48 states and very few issues backing the 5er. You do have to watch the nose swing of the truck as it does take some room. As noted above, it takes a large correction to start the backing turn, but one started, you have to chase or follow the trailer.
It is a bit different back a 5er compared to a travel trailer, but I much prefer the 5er. Seems I can get it into places that you will not get a travel trailer.
Amateur Radio Operator (KE5DFR)|Full-Time! - 2012 6.7L Ford Crew Cab Dually -2013 HitchHiker Champagne 38RLRSB - Travel with one Standard Schnauzer and one small Timneh African Gray Parrot