In my opinion Adcom amps are very good. While not being the best that can be had they do have a very good sound quality as long as the upstream equipment is good and they will not die. they will run for ever and provide you with years of music if you choose to go that route and to me the 545 series 2 is the best sounding of the Adcom amps and that comes from someone that sold Adcom in the 90's that got to play around with every piece of their equipment in different setups and the 545 II always sounded best to me but the 5500 and 5800 where good to and the 535 definitely had its merits as a good amp for the power ability and it was rated under what it could really do in a real world system.