@OP. Experience from an owner of JC1s and Pass XA60.8s - and familiar with the Class AB Pass's. I think its a worthwhile upgrade you are contemplating. But I would listen to the XAs as well as the Xs before making a decision. If your speakers are 4 ohm, you may not need as big a Pass amp as you think. I don't find the heat from the power amp to be objectionable and that's in a small room. However, I don't live in a hot climate so experiences will differ.
