@npole, I basically agree with you. The Perdix is great, but definitely not perfect.
I have asked (in various posts here and in email exchanges with Shearwater) for a variety of changes that I think would make my Perdix AI a better computer (for me).
- I would like to be able to set it to show the current Gradient Factor setting on the main (Tec) screen. I would generally only check it once, at the beginning of a dive. But, that is still more useful to me than some of what is shown there. And it is something that I would like to check on every single dive, so being able to have it shown on the main screen would be nice. Seeing it there would have saved me in the past from diving a different setting than what I intended.
- I would like to be able to set it for a Last Stop of 30ft/9m. A pretty common gas that I and my local tech diving buddies use is EAN80. For a lot of our dives, using 80% instead of 100% allows us to do our final deco a little deeper than 20', where we stay out of the surge/chop that is closer to the surface on rough days out in the ocean. It would be nice to have my TTS shown correctly, based on my dive plan.
- Have Gas Time Remaining shown reflect ALL stops that the computer is going to prompt for, whether they are mandatory or optional. My much-less-expensive recreational computer does this.
- Have Gas Time Remaining continue to show even once in deco. It would be okay with me if that was limited to only being shown when there is only 1 gas Enabled. I.e. you are doing a single tank dive, with no gas switches. My much-less-expensive recreational computer supports 3 gases and it does this.
- Support more than just 2 tank pressure transmitters. My much-less-expensive recreational computer supports 3.
- Have a setting for the tank pressure shown such that it displays T1 (transmitter 1) pressure when the first gas in the gas list is Active, T2 (transmitter 2) pressure when the 2nd gas is in the gas list is Active, etc.. Thus, when this setting is chosen, you could have the display just showing 1 tank pressure and it would automatically be showing the pressure of the gas you're actually breathing. I.e. you could perform a gas switch during the dive and not have to do anything else to see the tank pressure of the gas you switched to. My much-less-expensive recreational computer does this.
I don't know about anyone else, but my transmitters generally just stay on their respective 1st stage regs. And, I always use the same 1st stage(s) for back gas and the same 1st stage(s) for deco gases. So, it would only be a 1 time setup issue to have the computer know which transmitter is for my back gas and which is for deco (or my "other" tank in side mount).
The only day-to-day restriction it would add is making sure I actually set the first gas in the computer to be my back gas and the 2nd to my first deco gas, etc.. Which is not an issue, for me. I don't foresee it being a big deal for recreational divers who are only using 1 gas, either. In fact, it OC Rec mode, it seems like it could disallow configuration of more than 1 gas, thus making the whole GTR thing even easier (in OC Rec mode).
All that said, while the Perdix AI could be better (for my use and desires), I am very happy with it.
However,
@npole, maybe you should check out the Ratio iX3M. It might do what you want. It even has the option to connect an O2 analyzer accessory directly to the computer for analyzing your tanks.