I've owned Macintosh Solid state amps and have listened to Macintosh Tube amps. In my personal opinion the tube amps are more enjoyable to listen to. If transistor amps are superior or equal I don't think you would be seeing new production of old tube technology, specially given the cost. My current amp is a Music Reference RM-9. I think it also depends on what speakers you are listening to. I'm not saying high end transistor don't sound good, but given the choice it would be tube for me.