The Koni based coilover has a couple huge advantages... 1) is the big reason and that is the Konis dampers are definitely superior and work much better as a dual purpose daily driver and weekend fun car (where you want to stiffen the car on the weekend and it works really well) and 2) you can spec whatever spring rate you want. A good Koni based coilover will be just as comfortable as the BC setup when you want that but then the Konis can be adjusted for a weekend on track where the Buddy Club setup will fall short. And the key is that the Konis have an infinite (sweeps, no clicks) amount of adjustment; so you really can get whatever feel you want out of the car on the street, even if it's stiffer than the next guy might want it. You make it what you want it.
Chris