"He belongs to the most active and creative jazz-musicians in Switzerland. From early on, his own original compositions and working bands were the main focus of his musical work."
Michael Zollinger, 'Jazz 'n' more' 2/02

"It is the world-renowned pianist/bandleader George Gruntz who writes enthusiastic liner-notes in the newest album, about Herbie Kopf being his favourite bassplayer from Switzerland. It's not a matter of course to hear Gruntz revel to such an extent. And quite amazing for the fact that Gruntz is known to work with the finest acoustic bassists in the world, whereas Herbie Kopf plays the electric bass exclusively.
But Kopf is able to play the instrument with such a swing and drive, that it's hard to find an equivalent in the jazz field. Except maybe the great Steve Swallow, who switched from upright bass to the bassguitar almost 40 years ago." - Nick Liebmann, 'Neue Zürcher Zeitung', 6.6.2001