Map -> GPS = excellent analogy,
@tim2000s!
Thank you! Just to add to that, for me continuous recording like this does make managing T1 much, much easier. Not only do you know an approximate value for bg level, you have a clear indication of whether it's heading up or down, and at what rate it is doing this.
I know that one of the key issues with people using the Dexcom devices is the problem with Alarm Fatigue, and this is where I think the Libre has a big benefit. It isn't, and never has pretended that it is a CGM. So instead of worrying about alarms for heading high and low, you use it much more like you would undertake finger pricking. But instead of finger pricking 8-12 times a day, you scan yourself 40+ times a day. Because it's easy.
As a result, you have a much better view of how your glucose levels move about and where they are going. And that is invaluable for being able to make predictive correction doses of either carbs or insulin. It's also invaluable for understanding the effects of food. But you do have to choose to act on this. And that's the key. It is relatively expensive compared to finger pricking (well, maybe not if you were to use 40 per day).
What isn't recognised in all the cost/value reports is that it allows a change in behaviour. For the cost of two boxes of test strips, you can now observe yourself 40x per day for two weeks. If I was to do that using SMBG, I'd have fingers like a sieve and would have cost the NHS £446 a month in addition to what I do to calibrate the device now. That's the stat that is never talked about...