Originally Posted by shupe

I ran one in my last truck. I ran it for 6 months before selling the truck. If i hadn't sold the truck I would have pulled it out.

My observations of the no-slip:
Pros:

Traction - yep they're both spinning now
Install - ease of install
Price - less than the others (eaton, auburn, ect)

Cons:

Clunky / noisy (loud), sounded like the rear end was breaking daily; your passengers will look around like wtf!? when they hear it. Parking lots (change of direction, stopping)

Tire Chirp, plan on this if you ever decide to turn out onto a street while accelerating. Not an issue while turning on hwy

Disengaged and reengaging or unit or cycling - when you let off the throttle unit disengages vehicle pushed left, back on the throttle unit reengages pushing vehicle to the right (something like that)

I know you didn't ask for any experiences, but though I’d go ahead and add some anyway. I'd recommend checking the considerations section in the manual before purchase.
Powertrax No-Slip manual can be found here:
http://www.richmondgear.com/0002pdfs/8221001.pdf