I’m definitely in the “the more logging the better” camp. Partly I think it’s a UI issue, as hinted here:
Of course just a straightforward web-based log download would be better than nothing. In theory that could be incorporated into the existing data download files.
But now to the tricky part of network vs power outage. Rather than @kevin1’s fingbox method (which I do with UniFi), if you have something like a voltage-monitoring UPS with your network gear plugged into it you can log and send alerts during a power (Sense) outage. The voltage logging can also serve to keep Sense “honest”.
The most robust solution, which I think I’d be using if I was in PG&E-land right now, would be to use something like a Monnit voltage sensor on the Sense circuit and have a 4G LTE gateway service with that. The LiPo on the gateway runs for 24hrs stand-alone and it would be trivial to add some juice to extend that to long enough for major outages. An ethernet gateway would be cheaper but you’d then be relying on keeping your network intact in a power outage. Of course the real motivation to invest in something like that would probably have to come from needing other forms of monitoring like water leaks, pump failures and so on. I use Monnit for building/construction monitoring and it has saved some serious pain.