Since July 2008 I owned an ADAT ADT-200A. I tested the transceiver on my Optibeam and it works very good. It has a clear audio and the filters works precise and sharp. The reports on the band are always good. One of the best QSOs was Ecuador with 50 watt. Also the predistortion of the TX signal works well. It is a good digital transceiver without the need of a pc. I hope that within the next firmware, Hans implement some new features. He does a fine job !