I advocate servicing your regs when you experience ANY indication of a problem. And I advocate that you perform a thorough inspection of your regulators frequently including monitering IP. I do not suggest you wait until it becomes serious. I also do not advocate fixing something that is not broken as it is so easy to do more harm than good.
Your dive shop tech does not have a license. He might only have a day of training if he is even an authorized tech.
If you consider the reliability of a regulator over time and selected event (like servicing), the reliability of a regulator fall off immediately after service. To be fair, two things come into play there. First, if you service periodically, then you tend to be servicing a perfectly fine regulator. So it can come out of such service either still perfectly fine or with a problem (likely service induced). Secondly, there are usually only two prerequisites for becoming and "authorized" technician. One is you attend a 1 or 2 day manufacturer course on reg servicing. The other is that you work in an LDS. There are some very good and experienced tech out there. Perhaps you have found one. And there are techs that would have a hard time assembling a model car. I found a few I would not trust when I first started out.
The
highlighted statement above is the one that most folks don't understand when we get into these "discussions" regarding annual service, warranties, "Life Support", etc.
There
are some great techs out there, "authorized" and "unauthorized", working in shops or independantly. But you cannot automatically assume the guy (or gal) who services your reg during annual is uniquely qualified to do so because they've completed the "automatic-pass" 1-day course offered by the manufacturer.
For some "then versus now" perspective:
When I started diving in 1976, I asked the owner/instructor/service tech of my LDS as he handed me my brand new regulator how often I should bring the regulator in for maintenance. He raised an eyebrow, and when he saw that I was serious, told me "When it needs it, you'll know."
He then took the time to explain a little bit about how regulators worked, what to watch for, etc. He basically did for me what this thread now does for folks reading this board:
http://www.scubaboard.com/forums/4320058-post14.html
All regulators will need to be serviced. Some sooner, some later. I do not believe today's regs are so much less reliable than my mid-level reg from the '70's that they require annual service or they will fail. I
do think regs should be
inspected (by the diver) much more frequently than once a year, but a full service should
not by required annually in most cases. Again, refer to the link above regarding inspections that any diver can perform.
Best wishes.