I have been using Libre since last Christmas with the xdrip+ app (Xdrip+ is for android and Spike is IOS).
Never had a bleeder and never had much pain. The only really bad sensor I have had was when I tried it on my stomach. I place mine on the front of my arms - my biceps.
Having used about 40 sensors over 18 months G5 and Libre I now know that they vary. My last 3 Libres had 2 reading 15% high and one about 10% low on average. with a range either side of this average of up to 15%. Occasionally you get a rogue reading out side of this but not often.
One of the advantages of adding a transmitter and open source app is of course that you can calibrate it. Also in the States it will then run for 14 days. As mentioned above it is best to put it on 24 hours ahead. It will still run for the 10 days in the States and 14 days elsewhere.
I have a BMI of about 23.5 and never felt that sensor wire was not in right place.
There have been many discussions on the fb pages and forums as to where is the best place for the sensor and the thigh is mentioned a bit and one show off claimed the ankle is the best place! I find the back of the arm inconvenient because of putting on my transmitter and the danger of then knocking it off in doorways.
If you want to find out more about Libre plus transmitters read the article “All about CGM” on my website bgonmywatch.com .