I used them with H&R springs and they were fabulous. I wasnt in the market for Koni's like everyone suggests. However, the KYB's have lasted well over 2 years, (changed my suspension, and sold that setup to someone else) and had no noticeble dampening loss. I know two years isn't that long, but they've been just fine. I'm sure they won't last as long as Koni's though..
I have Koni's now with the GC coil overs, and I love em! my $.02