I just installed a Kartboy shifter in a buddy's 07 wrx 2 weeks ago. I mean, it feels better than stock I suppose.... but then he hopped in my car and he said "Wow, your shifter is still like half the throw distance of my NEW one".
Once you "set" it.... you don't need to adjust it anymore. Just put it where you want it.
I also installed F+R bushings in his car.
Then... I bought the rear kartboy shifter bushing for myself, as I'd never installed one. Worth every penny.
Cobb swaybars are simply Hotchkis swaybars re-branded and painted blue. However, they are 25mm, hollow (lightweight), and have 3 levels of adjustment on the rear swaybar. Exceptional product - everything you will ever need.
Do NOT install swaybars without the endlinks. 25mm sways with stock endlinks will bend then endlinks after the 1st pothole. Don't do it.
I've used both Whiteline and Kartboy endlinks.
The Whiteline broke the 1st day on the track... so I replaced it with a Kartboy set. It was less $$$.... and beefier, stronger, with larger bushings.
Kartboy endlinks are better.... period.