Mine seems pretty ordinary to drive under normal conditions, but when you stomp on it, it goes from 60-90 pdq, although it does have a little bit of turbo-lag.
When pulling, it is just plain smooth. In the hilly terrain I've towed in so far, I've locked out 6th, and it pulls most hills in 5th, shifting to 4th very rarely, never revving over about 2500 rpms. This is based on my vast 180 mile towing experience with it so far. If it weren't for the truck being a little more bouncy than usual, I might almost forget the trailer was back there.
It is quite different than pulling with the 4 speed 5.3L, w 3.73 Chevy I had before. I towed in 3rd mostly, and it would downshift to 2nd on many hills, (even overpasses when on totally flat land) and rev to 4,000 rpms or so in order to keep speed. Pulling up to the Eisenhower Tunnel west of Denver was a 40 mph, 4500 rpm, 235 degree event.
At this point, I'm in love with the Eco. Comfortable ride, spacious cab, adequate power and payload, decent fuel economy (20-21 60 mph hwy, 18-19 72-74 hwy, 16-17 daily commute, and about 10 towing at 55-60)