True. I was speaking specifically to gas loss by a physical failure though. Reliability of the transmitter is paramount. But, we've heard stories of stuck needles on SPG's too, so they are not exactly 100% reliable. How often does that happen? I don't know, probably not very often.
So far I've had one HP hose go bad that showed no outward signs, and was bubbling through the many holes in the outer case, kind of pretty, but little air loss and I replaced it shortly thereafter. Unless a diver pays no attention to the condition of their gear, it is almost impossible to have a catastrophic hose failure. I check my gear, so a sticking gauge would, and has, been caught. I also check gauges against each other on a regular basis. As long as you are looking for problems with the SPG system, you will find them well before a failure which, in my experience, will not be catastrophic. This is from someone that uses vintage gear that may be 40+ years old, and has dove gear on a number of occasions that should have been, and later was, tossed.
Nothing is 100% reliable, however digital electronics have a nasty habit of going bad, or disconnecting, without warning. Although you can do all the mechanical pressure and accuracy checks, there is no way to check the electronics that insures they will not completely fail on your next dive, which could be considered catastrophic if there is no backup SPG.
All that being said, I really don't care how another diver decides to set up or maintain their Kit.
Bob
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I may be old, but I'm not dead yet.