I went with CBI fab on my '04 up in idaho. I got them as a steal because the made an extra pair and they were bolt on. As much as its painful to pay extra for the bolt on, I'm totally sold. I had some fitment issues and they were really helpful getting that fixed up even though they basically sold them to me near cost. Steve is a top notch guy.
I think I've only actually dragged a slider once, so it maybe not justify the cost of them. As a person who has kayaks on top of their truck often, just having a full length step that runs the length of the truck and is very "high" near the body work is unbelievably helpful. I never really thought about it until they were on, and I'd do it again just for this feature!