It's reassuring to know that my pre-check success rate is somewhere in the middle based on the data in this thread. I'm 2 of 4. I don't have GE.

First time eligible (SFO): success, but got the hand swab
Second time (LAX): fail, sent to regular screening
Third time (SFO): fail, blue shirt guy questioned if I was even eligible for pre-check and I silently wondered whether I was too, based on 2 failures in a row.
Fourth time (ORD): success, no additional hoops. My first, complete, success.