I used the firmware update via the Bryston web browser interface. I'm now updated to S1.70, compiled 4-9-13, labeled as release candidate 1. I wasn't expecting a firmware update, since the official version is dated back in December 2012.
In the future, will the web interface be able to inform end users if it's a release candidate, beta, or final firmware before updating?
And, is it possible to update backwards? I haven't had any problems, but was just curious.