Sorry to bring up an oldish thread, but there is a lot of good info in it, and the device is current.

A couple of things caught my eye. First, the issue with cadence sensors freezing up is something I found in the setup instructions of the sensor. It must be oriented the right way otherwise the signal or the sensing, I don't know which, doesn't work well. I've been using mine on my shoe and it must be oriented so that the sensor's long axis is parallel with your foot, not at right angles. It is also important on the crank mount but I haven't tried that. It was the same whether using the Bolt, my phone or a computer app.

Second, using auto circumference is dead accurate in choosing wheel size. It eliminates the variability in the tires by measuring against a known distance using GPS, and it can do it over a longer distance than you would even measure manually. The only problem with this is when you use it on your indoor trainer. There's no GPS! But indoors it doesn't really matter as indoor miles and speed are just a guess in any case. Maybe your wheel traveled that far, but would your power output have taken you that far? I always just take it with a grain of salt, but still include it in my totals as there is nothing else. And in the case of Strava showing a different result, it probably used the GPS data to get distance.

Overall though, I agree with the general opinion of the thread, this is a great device.