I agree the manual shifts are not as quick as I would like...BUT after you figure it out it still works better then "hang shifts" that come with the Sport mode.
BTW I always manual shift when off roading, not so much if just cruising down some dirt road, but when I'm in Baja mode (that's me not the truck...) I can short shift, or let the RPM drift upwards a bit to suit the situation...
While I agree manual shifts are extremely slow to respond, I find the way it holds RPMs excessive for some situations, and then manual is the answer. I particularly like manual when I'm in Baja mode. I find if I'm hustling in sport on pavement I'm hustling the whole time and full auto is OK. When i'm hustling on gravel or offroad in Baja, there are frequent times where I want to hold my speed or slow because of trail conditions, and then juice it, and then hold, etc... and in auto it gets tiresome having the motor hold at 4.5k rpms while I'm negotiating a particularly rough bit. I definitely like sport with full auto when I'm giving it the beans from a standstill. Shifts are satisfyingly firm.
Gear lockout feature seems applicable to this conversation as well. In auto, pull the downshift paddle (left) and the cluster will show 10 gears available, and the gear you're in. Pull the upshift (right) paddle, and it will close out 10th gear, pull again and close out 9th etc... Nice for towing, driving a hilly highway, or cruising 2 lane fast but sweeping road and you don't want to be in tractor mode in 10th gear.