Service frequency is a topic of constant debate on watchuseek. I've seen enough photos of watches that people let run until they were broken to want to know I don't want to do it to mine. That said, I'll probably never service my Seiko 5 either before or after it breaks, and I'll service my MKII every 4-5 years because I actually dive with it. I'm disinclined to take the word of a jeweler in whose best interest it is to maximize service fees on whether servicing should be done before or after a fault is developed. After all, I'm sure the Mini dealer would love to tell me the same thing, given the relative costs of oil vs. engine replacement.