I have recently got one, and am now on my second sensor. I only bought one because my healthcare team could not seem to get me on a good suitable insulin.( still not good)
My first sensor was very good until it got to 10 days after 12 days it was so far out I stopped using it. After calls and emails they sent me a replacement. My present sensor is working much better with 3 days left on it.
They are good and can help to avoid hypos. The graphs it shows are usefull to improve control. So easy to scan and wonderfull during the night, I dont even turn the light on. Expensive though, I hope the sensors last 14 days.