Welp... Darn. Something I had been fearing since the beginning of this, "pinch me, is this real?" journey looks like it might actually be happening. I say, "pinch me, is this real?" because GS/3 temperature performance, with stainless boilers, groups, and portafilters, at 1/5 the cost was (and still is) utterly unheard of. Immediately, the detractors started telling us that Breville is a home appliance company and the BDB "will not be user serviceable". Of course, since it is assembled by hand, it is completely and utterly user serviceable. But the detractors were not totally wrong. While it is pretty straightforward to repair, availability of parts could most certainly be an issue. Up until now though, it has not been a large issue, because over time, we discovered that the common wear items, o-rings, solenoids, and steam ball valves, are readily available, even if not from Breville themselves.
Up until now... because it looks like the end of the road for the steam ball valve availability.* And the steam ball valve is one of the regular wear items that needs periodic replacement. Now, having said that, it is a virtual certainty that the ball valve itself is actually not a custom Breville part, and the world is awash in all manner of ball valves that will do the job. So keeping the BDB going is not going to fail for lack of a steam ball valve, but...
...here is the part that worries me most...
There has not been a new BDB since the 920 was introduced around 2014. Late 2011 gave us the 900. Late 2012 gave us the 900/B, which had the 920 brew group, (or rather, the 920 has the 900/B brew group). And sometime in late 2013 or early 2014 came the 920. Those dates may not be exact, but the point is, there has not been anything new in the BDB series (beside the Oracle), for nearly four years now. On the one hand, maybe that means they got it to the level of optimization they wanted. On the other hand maybe it means they are winding the BDB program down to eventually cancel it. I have a serious concern that it is the latter. And besides the lack of anything new since 2014, another reason I think so, is the discontinuation of common maintenance replacement items, in this case the steam ball valve.
*I will grant the possibility that Breville has cut ties with the original ball valve supplier, and the interruption in supply of them is related to the logistical headache of switching suppliers. But in the absence of any supporting messages (which I do not expect), this remains for us long-term users, a worry about Breville's future plans for the BDB.