All excellent points, Cleavitt. I've often wondered where these urban myths get started. I figure it goes way back to the very early days of dive computers and a natural resistance to change. Nobody wants to come across as pig-headed so it's easier to just vilify the new technology and dismiss it.
I remember going to my LDS back when Nitrox was just starting to get some attention. I asked the owner about it. I'll never forget his response : "Nitrox! You must be crazy. This dive shop will never, ever supply that Devil Gas." Yea. "Devil Gas." They actually called it "devil gas" for some bizarre reason. By the way, that dive shop is still around and pumps hundreds of tanks of Nitrox every week now.
I've asked repeatedly here and other places for any kind of data associated with computer and transmitter failures and all I get is "Well everyone KNOWS they're not as reliable" or "I knew this guy who was on a boat with this other guy and (insert catastrophic failure here) happened."
It comes down to this: There is no data to indicate that computers (wireless or otherwise) are inherently less reliable than a gauge.
-Charles
Actually, that is not quite true. Each mfg or retailer does, but is very unlikely to share that information unless it was better that an SPG (which it isn't).
It would be easy to say, that electronics are obvious more reliable than a moving gauge, but you are comparing a fairly new technology versus a very mature one. And a more complex system to a fairly simple one.
With an SPG, one may get one with a quality issue, or a really cheap design that does not last, but all of the issues on how to make a reliable one have long ago been identified and corrected.
Since getting a wireless system, I've have two sets of transmitters and three computers replaced for design flaws. And I happen to know that there is at least one more design correction has been made from what I have.
During that same time frame, not one design flaw was identified in a SPG.
I suspect that within the next few years (hopefully), the technology will get to the point where the only issue is the quality of the build, but we are not quite there.
While most of the issues have been with the electronics, one of them was due to a physical design issue. All the original transmitters were made from a brass that was a different alloy than the brass used to make most first stages. Air got to the transducer via a tiny drilled hole, which if used in salt water for a lot of dives, would have galvanic corrosion plug the hole. Dive in fresh water, or only use the unit for a small number of dives (under a couple hundred) and one would never see the issue.
The problem was, once plugged, there was no way to clean it, as debris would be pushed into the sensor.
Today, that design has been replaced with a removable orifice, that can be cleaned.
Another design issue was a low reliability switch that would leave the sensor on once the pressure was removed.
I would guess, that if one buys one today, and does not dive a lot, they they are now getting somewhat close to a stable design, but if you have had one for any length of time, and used it a lot (say 500 to 1,000 dives), you will tend to be a bit nervous about just using that to monitor pressure.
