I disagree with specific auditioning methods, comparing listening at a dealers location and then in your own home, just doesn't add up for me.
It seems that I was addressed regarding Spectron and a new model, firstly I was not "scared" that Spectron will introduce a new bla! bla! You are being very naive if you think this is the last amp and all you have to do is take a look at their past history, need I say more.
If you are going to listen to Bryston 28 SQ mono blocks I would recomend you have them plugged into Torus RM20 conditioners at least, one for each amp if you really want to hear what these can do.
In the end just make sure what ever it is that you are demoing make sure they are well broken-in, compared in your own set-up and enjoy.