Save your money and buy an ARB, it will be the smoothest on the road, you wont even know its there, because it will be an open diff until you engage it. Yes the ARB does cost a little more than the others(about 2x as much as some), but it is the best thing you can have in a daily/trail rig. You can also find them used a lot cheaper. I think I seen one in the used parts for sale section on either Pirate4x4.com, or MarlinCrawler.com(forum) for $350, it was still in the 3rd member w/4.10gears. You can also get them set-up w/gears from Marlin, Trailgear, or Davezoffroad, for under $1500. Davez Offroad sells complete 3rds w/gears for about $1150+shipping and exchange.