Until recently, I would take both sets of my regs in every year to be serviced. Both are under warranty, although one set is over 20yrs. old (one 2nd stage is over 30yrs old)--with Lifetime Parts . The second set is only a year old, and I want to maintain the warranty which will expire in only 2 years.
I wasn't that surprised to learn most failures occur after service. Both times that my old reg failed, it was due to poor service. The first time, I took it in thinking they'd "overhaul it" because it was breathing hard at depth. As far as I could tell, they didn't do anthing. On the first dive, my exhaust valve split due to overbreathing in a hard current at 70'. It turns out that both the 1st stage and the 2nd were contaminated from bad air in Mexico (carbon). Neither had been cracked open. It made for an interesting beginning to the dive, but I managed to borrow a reg to finish it out.
The second time it failed, it actually failed twice. The first time was on the boat, when I thought the o-ring gave way. I replace the ring, everythign looked fine, then I drop in. At 30', a big blast on the back of my head suggested another ring went bad.
I tried fixing it on the boat only to learn it wasn't a ring. Back in a FL LDS, I learned the seat in the first stage had been crimped. I when I took it back to my own LDS (different one than the first time), they said, "But, we never opened it up!".
They didn't? Funny, I paid for a full overhaul and got a bag of parts back. Either way, somebody was lying or somebody screwed up.
Both times, btw, the service took 4-6 weeks.
Last week I took my new rig into that shop again--the site of the purchase. They told me 2-weeks minimum. When I protested, pointing out that the reason I bought a new reg was to avoid the long delays due to "hard to find old Oceanic parts", they agreed to have it in a week. Now, I'm afraid they'll either rush it or not do anything.
When the warranty runs out, I'll look into DIY. The other reg is an Oceanic/SP combo. I'm skipping the service on it this year and if I can find the parts, I'll DIY, as well. I agree, it isn't rocket science.
I was going to give the old reg to my newly certified son, but he's getting a new setup, either XS SeaAir or Poseidon.