I looked at a lot of lift kits before I made a purchase, and some are cheaper than others and some are made to use off-road while some are just for looks with no function but raised height.
The Skyjacker kit is a very nice piece and is worth the money if you need/want all the adjustabilty and you want to use thier springs.
Pro Comp also offers a great kit if major axle attriculation is your goal.
I chose the Tuff Country kit because I wanted to retain the factory springs front and rear. None of the lift kit manufactures that I talked to said that thier rear springs had the capacity of the factory pack ( they were purpose built for lift and wheel hop control, not for load capability ) . The front springs seem to be a middle of the road range in capacity from all of the manufactures and focussed mainly on ride height and flex- not capacity. The ones that I spoke with said that they would sag with a heavy bumper and a heavy winch.
So it seemed that I only needed 3" of lift and in order to keep the truck functional so I went with the Tuff Country stuff. The spacers are not the super cheap urethane death traps that some manufactures use, they are made of thick gauge steel and are bolted in. The control arms are thicker and stronger than the cheap factory stamped steal pieces; they are not as good as what the adjustable ones are, but not everyone needs them to be. The rear is a good set up ( in my opinion ) if you want to keep the factory springs and gain a small amount of lift; unless you called up National Spring and ordered a complete pack .
If used hard, a truck with the cheap spacers can loose a spring and make things bad real quick. I almost did not lok at the Tuff Country kit because of that, but than I saw how the springs were retained in the 3" kit and realized that it would be next to impossible to let a spring come out the way it is made.
I have seen trucks with the hiem joints in the control arms break the factory brackets from the axle housing ( welds ) , so sometimes you might be moving the weak link to somewhere else. A urethane bushing may have gave a little .
Just because a kit is not the strongest on the market might not mean that it is cheap. Some kits are designed for certain purposes and some aren"t . I know that there are kits out there that use "spacers " and they are a rolling death trap waiting to happen, but not all of the spacers are the bad ones; the T/C ones are bolted in and in my opinion are not in that death trap catagory. JMHO , Thomas