Regarding the 10spd trans (6.7l), I am not totally thrilled with it. Drives perfectly fine around town or normal throttle application and I like the way it shifts in this application (very smooth). The fuel mileage is also excellent.
However, as soon as you add throttle especially medium to heavy throttle inputs, it does not seem to know what gear it wants. Also, If you floor it from a stop it cuts all the power and does some weird things, then all the power comes back and abruptly shifts through the gears. It could be the torque management programing, but I find it weird how it acts. Sport mode does help some, but the transmission is not smooth is these type of throttle inputs. I now have 2800 miles on it now so I doubt it will get any better.
My 2015 6.7 was definitely better, but it had it own jerky shifts under the same type of throttle applications. When I floored my '15 from a stop it would not play dead, you could feel the reduce power in the first 2 gears, however the truck accelerated quickly. Hopefully they will come out with a program update.