I use manual all the time when I am towing our 34ft 8500lb TT except when in towns or cities. The engine is capable of pulling far more per gear than T/H mode allows for especially when you get into some nice rolling hills. I hated the way it kept going down to 2nd when 3rd was good or 3rd when 4th worked just fine in manual mode. Now when I am hauling the flat deck with 8000lbs of water on it I use T/H as it is mostly flats where I haul and the puter does a nice job with the shift scheduling.