Knob mod optional, in my experience. I had no trouble getting the knob on the rear adjusters after I peeled back the carpet and pad at the top of the tower. No carpet cutting or anything required, either, and you can't see that the carpet has been jacked with.
I've been running at 1/4 turn off of full soft with Roush springs. There is more harshness than with the stock setup, but I don't think it's much worse than when the stock setup was new. Handling and grip were much improved. I may try some adjustments now that everything has settled in a bit.
