The dampers have very well known problems, and they have no QC.
I ran KSport Kontrol Pro coilovers on my old Maxima. They had horrible customer service, and the product just isn't quality.
They also appear to run off 1/4" or 1/8", which is horribly slow. While I am not interested in hopping up and down, I would rather not wait a full minute to get from aired out to ride height. That's borderline rediculous.
YouTube - Maxima with K-Sportracing Air Suspension
Vid of a guy from Maxima.org (he's european), showing his off.