They can be useful, but are limited to use in 4LO and 12 mph maximum, while 4LO itself can be used up to 30 mph.Is it worth it? I wont rock crawl, just some mud and light towing. If cost wasn't an issue I would get the Pro 4x. Just trying to get best deal on a base 2011 cc 4x4 Titan or Pro 4x. I would add lift, wheel and tires later. Any advice will help!