Looking on the H&R site they don't appear to be adjustable.
I have had H&R susp. parts on 3 other cars. A smokin deal provided me the the MS coil over set up and camber links last summer.
I started out in the recommended mid range adjustments, which I found quite nice for daily driving even when fully lowered and still noticeably better than stock. After maxing the settings for both rebound and compression there was another noticeable difference. The ride is harsher now but even more fun in the corners/backroads and even the occasional stop sign launch.
Easy to adjust except for rebound in the rear, but that still does not take long to get the dampers out and back in.
Ron Tonkin was offering the MS set up for $1400 recently on another 3 site.
Enjoy what ever you decide on.