I've used FreeStyle Libre on and off for 6 months. I periodically double-checked with finger prick sugar tests, which have been fairly consistent with the results from the FreeStyle Libre.
The major advantage of using this system is that I actually get a lot of feedbacks from my everyday life and how it affects my sugar levels. How the kind of food I ate, the timing of meals, the kind of activities I did, and the timing of medications affected the sugar levels.
One of my diabetic pills was discontinued because hypoglycemic episodes were detected persistently at a certain period of time. I don't think it would have been picked up that easily if I wasn’t using this system.
Another surprise I found at another occasion was my sugar was low even after drinking some sweet red wine, which wasn't what I expected to happen. After some looking up, I found that alcohol can promote the action of one of the diabetic pills I took, which was a good thing to know!
The continuous readings have taught me and given me confidence in controlling my sugar levels well. So this is also a therapeutic tool.