Quick update. I now have 15,000 trouble free miles on the truck. I added an Edge EZ and I run with synthetic oil. I can now get as high as 24 mpg if I can roll along at 55-60 without any stopping. The norm is more like 22 hwy and 18.5 city, subtract 1 mpg when running with winter blend fuel. The Edge EZ definately gave me at least 1 mpg better, maybe a bit more.
I now have 22K miles on the truck without any trouble. That 23 - 24 mpg at 55 with no wind and no stops, etc has held true, but remember, that's a pretty unrealistic scenario in normal life. I just said it to show an absolute best case scenario. Real world was more like 20 Hwy and 17 city this winter under the best conditions and 2-3 mpg lower when in 4x4 with snow and very cold. Still, I think that's very good.

Somethings I've done so far that helped improve my economy. (1) Got rid of my lead foot. Seriously, just keeping a real light foot and slower speeds added as much as 2 mpg. Watching the DIC helped me learn to change my habits. That said, the following mods got me another 1+ mpg. (2) Edge EZ running on level one. (3) Boost Stick, but only when combined with the blocking plate and finger stick to bypass the EGR system. Boost stick with a functional EGR had fuel economy go down. the boost stick has helped towing, but doesn't seem to effect my economy empty.

The mods definately helped my economy towing, adding as much as 2 mpg depending upon conditions. I can get 14-15 pulling my 34' x 8' x 9' goosneck horse trailer (10,000-12,000lb) just going 50 mph on nice back roads w/out starts and stops. Pushing that up to 65-70 drops it down to about 11mpg and pusing up to 75-80 takes it down to about 9. As a rule of thumb, economy seems to drop about 1 mpg for ever 5 mph over 55.

I will be adding a corsa perfomance exhaust w/ down pipe soon. I'll let you know if that makes any difference after I've had a chance to observe it in action for a while.