I know folk who have used them & been very happy. I've just fitted 20mm bolt to hub spacers myself & like the way they look. Only driven about 3 miles though since fitting them.
diff opinions on spacers as discussed many times before..i didnt like them on mine but there are lots of guys out there using them with no complaints...
I'm using 20mm bolt on Eibach spacers (might even be selling them before the year is out) front and back with the standard bolts that come with the car and had absolutely no issues.
They definitely make the car look how it should imo!