Yeah right, "if you are paying attention" and everyone does that and knows how to do that and it works every time.It is rarely catastrophic failure if you are paying attention...
"Catastrophic" isn't always the issue with the regulator, it is the reaction of the diver to the "non-catastrophic" issue that can be catastrophic.
Not true all the time and it "will exhibit signs of needing service" at the least opportune time like right in the middle of expensive dive vacation.A regulator will exhibit signs of needing service as well as simple checks will verify proper operating conditions...