I've put a thousand miles or so on one. It is a well done truck. The 8 speed trans is very good, power is great, the Alpine stereo is incredible, and most of the bells and whistles (nav, heated/cooled seats, air suspension, etc) are fun to play with. It's comfortable and great on trips too.

In mixed city/highway driving I got about 24mpg with it, a 4x4 crew cab Laramie.

Only minor complaints about it:

-you can hear turbo surge when you tip out of the throttle at low speed and high load (like brake torquing, or trying to move a trailer around, etc).

-at midrange altitudes (Denver, Idaho Springs, Flagstaff) it has noticeable turbo lag when taking off from a light. It has a little lag on launch at sea level too but it isn't objectionable.

-if you tip in and out of the accelerator pedal a lot, you'll occasionally get driveline clunks.