I agree with what some other folks have said. If you have the option of getting them with the rig then go for it. I would probably fork out the money to get them installed if I could find someone to do it around here. My next rig (when ever and whatever that is) WILL have them.
In the mean time though I've cut down setup time with leveling with these two deals:
Anderson levelerCamco leveling scissor jack socketThe scissor jack socket just goes in your cordless drill. I always bring my 20v DeWalt cordless drill with me. Don't use the jacks for leveling but zipping down the jacks in 5 seconds makes setup time faster anyways.