So far mine are working great and make a big difference in getting everything slowed down in a hurry. The most common complaint that I have heard is that some guys had a hard time bleeding the system. When it comes time to do yours you might want to try this.
Since you will be plumbing for a fluid return from the solenoid you can use the port on the master cylinder to apply pressure on top of the fluid. I used a Mityvac...
http://www.mityvac.com/pages/products_hvpo.asp#
and a helper to keep the pressure pumped up. A few pumps, crack a bleeder valve, few more pumps, no more air, close the bleeder valve, add more fluid to reservoir and repeat. 5 minutes per wheel.
The Mityvac didn't work for beans when used to pull a vacuum at the bleeder and the method given in the actuator instructions; "insert screwdriver in Slot "A", engage Tab "B" and make like your churning butter" wasn't any fun either.
Can't wait for the pitchurs.
Steve P.