Shane,
I just did the OME 779/781 (with firm shocks) lift on my '04 DII about a month ago. Long and short of it, I have no regrets. The ride is definitly firmer but much more controlled. I carry approx 300 lbs of gear, plus passangers and tow a trailer with a tounge weight of around 400-450lbs pretty regularly and the OME springs handle this weight much better then the stock set-up. I had a TJM bumper installed about a week before I did the lift and the weight of the TJM (no winch) caused the front end to bottom out over fairly insignificant bumps (ie. coming up a driveway at anything but a crawl).
Regarding on-road characteristics. I have seen no tracking issues on the freeway. I was concerned about this as my wife drives the truck daily but have had no noticable problem. Cornering is much flater and confidence-inspiring. Step-in height is (expectedly) higher due to the lift & 265/75s. It is enough that my wife complains about it fairly often. No problem with alignment or brake lines at full articulation.
Overall I think the OME springs/shocks transform the DII into the truck it is supposed to be. The ability to carry cargo is improved, it drives better and with larger tires gives you increased clearance which is definitly noticed on the trail.
Lance