mike wrote :
I see they use a 'phone-type WAN to send the data to supplier - good
if secure I suppose.

OVO installed SM's here in June...

Pro
1. You know exactly what your consumption is second by second on the
indoor display.
2. You know exactly what your consumption was every 30min, per day, per
week, month recorded/ stored via their web site.
3. You no longer need to look at the readings and let them know, they
are uploaded every night.

Cons
They, or if hacked another, could cut you off in an instant. Risk tiny.