Hi,
I have had my MS spings and camber plates installed for 8 months - maybe 8,000 miles and I have to say they are very nice. I wanted a progresive spring but one that did not lower the car more than one inch. I had a Miata that was super low and hated speed bumps with a passion. To my knowledge most other spring dump the car more than an inch or 25mm so they were out of the question.
As for the ride - it's not stiff but it is firmer than stock, it goes around a track just fine with a little swaying but I still have the stock swaybars on it. I might change those next but for the $400 (springs) it is nice. The coilovers were a little pricey and when I did mine I could not find any reviews of them. I measured the car before and after - it was about a 1" drop in front and maybe 5/8" to 3/4" in the rear.
Cheers!
Peter