@Caveeagle
The problem with dive shops doing a diagnostic check as you say is, if a technician performs an inspection outside of a manufacturers recommended service interval, they are shifting liability from the manufacturer to themselves. If a failure then occurs and there is an injury, who is to blame the manufacture who suggested a full rebuild or the technician who said it was safe to dive? I personally am not willing to risk the shop that I work for, or the jobs of my co-workers, much less my personal career and finances. Frankly, because I see how well people "maintain" their gear. Pleas don't forget, this is not just sports gear, this is life support and should be treated as such.