I went with the front because it was cheaper and at the time I was looking at that or a leveling kit. Also at the time the only thing available for the 3rd gens were the front and the rear 4 link - no rear 2 bag system then. I can't afford the 4 link.
I expect I will do something to the rear, but unless it rains money it will probably be the 2 bag. My truck rides pretty well with the BFG 315's now, but it could always ride better.
Milage. . I think around 18-19 usually. I haven't calculated it in awhile and my overhead computer is off because of the EZ. RPMs at 65 are probably around 1900 or so. A bit low for towing, but great for commuting. If I were to do it over again I would of gotten 4. 10's with the automatic. But I didn't expect to be putting the larger tires on.
The front will come in real handy on Monday as well. . My 240 lb Buckstop bumper arrives, and as soon as it goes on I can just add some more air to level the truck out again. I also bought it because I'll probably get a snowplow sometime in the next couple years.