I'm surprised by a number of the failures, such that I did wonder if the failure might be happening on the speech recognition side rather than the response gene

I'm surprised by a number of the failures, such that I did wonder if the failure might be happening on the speech recognition side rather than the response generation side. Both Google Home and Alexa have very little problem recognising my speech whilst friends often struggle even when they seem to say the precise same phrase, to the point it's mildly entertaining. With Google I suspect they've tailored to my voice (I've used voice commands extensively for several years) but I've only had a Dot briefly and it worked well from the start. Another surprise is that they cope well with my perculiarly English English phrasing and pronunciation, but I'm sure there are lots of less widely spoken dialects that would throw them.