I tend to avoid reporting when unnecessary, sometimes I'll watch replays to ensure that the silver Aerospray with zero splats, three deaths, and 130p of turf was not, in fact, throwing intentionally, but it's never ended up with anything being report-worthy.
There is one time I did report someone, a Heavy user who seemed to be aimbotting. They could have just been cracked, but they didn't miss a single shot in the replay, and I was only in A rank at the time. (Happened roughly a year ago.) I've had no similar encounters since. Why risk cheating when you can just use the .52 Gal anyway?