[Bad Dawg]

We have the 4" Rancho lift (see the thread on the "Technical Discussion and Customizing your H2" called "Full Throttle Suspension". I explain the lift a little with a couple of pics.
Basically it ends up over 5" of lift, not counting the tires difference. Because of more body roll I run the Rancho 9000's and have them set at about 7 (there are 9 settings). If you are used to lifts like you said then I expect you already know about the extra caution on side hill driving. I went with the larger tires when we did the lift, so I can't say if the lift had any affect on milage. We currently average about 11.5 mpg + about 6 - 10% because of the difference of the tire size (we haven't recalculated the computer for the tires yet). Hard braking is a bit more interesting because of all that weight higher in the air. Again, you know this stuff because of you past experiance with lifted j**ps.
The added ground clearance of the body and chassis is great but the suspension clearance is only achieved by the tires.
Towing shouldn't be a big deal with the correct hitch set up. I firmly recommend a load-leveling hitch set up. I pull our race rig with a lifted Dually Duramax and the difference between just using a simple ball hitch and the load leveling system is night and day!
I'll attach another picture here of our rig (HumDawg).

You can never have enough horsepower! Yellow LUX, Airforce intake, stainless headers and exhaust, Gobi rack and ladder, roof mounted off road lights, full wrap brush guard, rear light guards, outside tire carrier, Rancho 4" suspension lift, Ultra "EN4CER" 17x9 wheels, Goodyear 37/12.50R17 MT/R tires, removed side-step bars, 9.5ti warn multi-mount winch.