I love my M030 suspension. Put it on last year and haven't regretted it a bit. The ride is slightly stiffer, rougher, but the increased handling is worth it...lower center of gravity, stiffer springs, etc. Since it lowers the car slightly (10mm and 20mm IIRC) you also get, IMO, a better overall look....less gap in the wheel well.
I've been on several long trips with this setup and the increased stiffness in the ride is not bothersome at all...unless you're on extremely rough pothole roads. Very noticable there, but otherwise, the ride is quite acceptable. Of course, that may be simply justification for having done it too! I'd suggest trying to find some cars with these setups, going for a ride and see what you think.
I haven't checked recently, but at one time there seemed to be a shortage of M030's around and people were having to wait a month or longer for them to be shipped to the US. I got lucky and happened to get the last one that Suncoast had in stock at the time, according to them
Bob