I've tried both, not on a Berg though, and I think they suck comparing to Alders slipper clutch (aka Husabergs own in power parts).
The Adler cluth is easy and I havn't got tierd in my left arm when riding for a whole year Suter and STM är more like a stadard clutch.
We use both SuterRacing and the OEM Slipperclutch supplied by your local dealer, and we recomend the OEM if money is not the issue here.
Price wise the Suter does the same for 1/2 price but the disadvantege is that its harder to tune in, specially on the 650.