I've owned the Kitargo mono extremes for about three years and have had zero problems with the amps I'm currently running a pair of Ruark CL30's and they sound great. Prior to this purchase, I owed Arcam amps which left much to be desired. Over the past three years of dealing with Klaus he's been excellent. His customer service is the best, and he returns my calls and e-mails promptly. We've spoken several times at the Capital Audio Fest at length. Presently, I'm in the process of upgrading to the Kismet monos and looking forward to it.