James - first of all - happy new year wishes to you. All the best in 2016!
And second of all - I can't express enough how much I am enjoying listening to my newly purchased 4BSST2 and the exquisite Bryston DAC.
And thirdly - obsessive long time audio guy that I am (explains why Bryston is at the top of my list) you have me very intrigued regarding retrofitting my new 4BSST2 to cubed version. I would be delighted to participate in any possible beta test of such a retrofit - I would gladly drop my 4B at your doorstep/loading dock in Peterborough, pick it up, and subsequently contribute to any follow up you might see fit.
In any case - could you please put me at the top of the list for squared --> cubed upgrade. Such a happy customer I would remain.
(Maybe we should start a new discussion thread on squared to cubed retrofit).