I just picked up this short throw shifter, and the difference between this and stock is night and day.
For reference, I have a 2003 WRX sedan, with a bone stock transmission, except for Kartboy front shifter bushings, and this Mode SS. Looking at pictures side-by-side, I'm pretty sure this is identical to the Cobb Adjustable short shifter. They're even the same price.
Installation was very straight-forward. Mode includes excellent step-by-step instructions with the kit, so a how-to writeup really isn't necessary. The only difficulty I ran into was popping the new shifter ball into the spherical retainer at the bottom. Mode recommends using a mallet, but I found that just man-handling it in with my hands worked better.
Adjustment is a piece of cake. Simply extend the lower section of the shifter to tighten up the throw. Once you're happy with that, extend the upper section to where the knob feels most comfortable. Mode recommends trimming a small section of steel plate that holds the rubber boot below the shifter in place. This prevents the shifter linkage from scraping against the plate and you can tighten up the throw even more. I didn't have any good way of trimming it during the install, so I just adjusted the shifter as close to the plate as possible without interfering. (1st and 3rd gears bring the linkage the closest to the plate). Even with just that, I would say that the shifter is about as notchy and tight as the Gen. 1 Miata I used to have, which is quite a complement in my book.
I would definitely recommend this mod. It fixed all of the complaints I had with the stock subie shifter. I haven't tried the Kartboy, so I can't compare the two. I know it's about $50 cheaper, but the adjustability is what sold me on the Mode shifter. I bought it from RallySportDirect:
I adjusted the knob height (snicker) to the lowest it would go, and with everything put back together, the knob seems maybe .75-1" lower than stock. It's not much, but it looks classy, and more importantly, is about the most comfortable position for my reach. In fact, I might raise up a hair just to get a little bit more leverage on the throw.
I guess that's about it. I'll post up some pictures later. I just got an DSLR and am looking for any excuse to use it!