We have purchased a set DEMA balls in November 2012 for our home Ullrich foosball table. The previous balls have suffered from the weekly training a bit and had to therefore be replaced so slowly. As a measure of ordinary balls we look at the previous, supplied balls, and played in the Stuttgart pubs balls (eg Oblomov, Zwölfzehn, Libero ...).
Unfortunately, the DEMA-balls our demands were not fair. It can be controlled though and cheat with you, but they are more difficult to control than the usual balls. The balls are very tough and fast and therefore less suitable for tech savvy game. After a short test phase the balls are therefore again went back.