I just replaced my shocks with a set of rough country's off ebay, great price, only 139.00 plus shipping for their 9000 series nitro shock. I'm sure someone else will chime in, but look for abnormal wear on the outside of the tires (slight cupping), and more of a "bouncy" feeling when you hit bumps. It was a night and day difference after putting these on. Going over the same bumps, what used to take 3 or 4 compression/rebounds now take about 1.5x's with the new shocks. Less dipping in the front when braking too.
As far as ease of installation; I didn't even jack the truck up. Rears went on with no problem and the fronts were put on by turning the steering wheel to full lock one direction, replacing the shock, then going full lock the other way and doing the same thing.
Hope this helps and good luck.