I am certain these add 15 horsepower and 3" of additional articulation. Actually they just look cool. When I saw them I had to have them on my new Jeep, and figured I'd find some way to make them work. The transfer knob fits easily but I did have to cut the shifter bit shorter to fit. Hack saw was fine then a sanding to smooth it off. Otherwise they fit fine. I love the tire tread, and the billet aluminum matches the interior much better than the stock simulated chrome.
These are the Drake JK knobs on a 6-speed. I think they say they work up to the 2010s.
I did have to break the stock transfer knob to remove it. Instructions say to pull harder still, and indeed that its what is required. It just never felt like it would happen.
It is a bit gut wrenching to use heavy tools on the interior of a week-old vehicle with under 300 miles on it.