So far I have put 900 miles on my new 4.56 gears, installed on Monday the 14th (a week ago).
Around town its rev happy, no more sitting in gear waiting for the RPM's to get going. I havent driven around town enough to give a good MPG estimate but from looking at my ultra-gauge, seems like 1st-4th gear the gas gets sucked a little more (I do get to speed a lot quicker). Now I can actually drive around town in 5th gear and going 45-55 MPH I am showing around 36-39 which equates to 33-35 after the over gear correction.
On my trip to Primm from Phoenix, I was driving between 70 and 85 MPH with mostly head winds and cold weather. The whole trip I averaged just a bit over 20 MPG and engine load in the 70-90% range. I also did a few trails on the way with some quick starts. I had about 500 pounds of passengers and cargo in my 4 cylinder access cab. I noticed that up certain hills I no longer had to downshift and when passing, I was able to just lay into 5th gear and accelerate.
Over all I am extremely happy with my choice of re-gearing and the gear choice I went with. People should really consider re-gearing to achieve their lost power needs instead of looking to do CAI, exhausts and all the other expensive things that do not achieve much if anything.