Lowering Springs...

Does anyone know anything about Tenzo-R Lowering Spring kits? This is the link to their page: http://www.tenzoracingsports.com/sus...ngs/index.html

I was wondering if anyone knew the quality of the parts and ride. Right now my choices are Eibach Sportline, Neuspeed Sports, or these Tenzo's. I would like an opinion on which is the smoothest ride. Any help?

Scott