As as diet and metformin controlled type 2 I've found the Libre extremely useful for confirming and/or identifying patterns in glucose levels. However I consistently get lower readings (around 1-1.5 points) with it, and according to it's predictions I'm well into the non diabetic range, while my meter tells me that I'm at best pre-diabetic as do my HbA1c results, so I've tended to use both methods in tandem as I don't feel I can trust the Libre on its own, and this makes it a rather expensive exercise on my pension.
But certainly for seeing what, how, & when my body reacts to certain stimuli I consider it a minor miracle, and can imagine that it must really help with insight into insulin management.
Robbity