As far as I know, all Suunto computers implement the same algorithm in the same way. From my own experience, I have compared my wife's Cobra with my D6 and seen that both computers indicate the same no-decompression time during each dive. I suspect the Zoop, Cobra, D6 and D9 and whatever else Suunto may offer are all the same as far as their core functions. What differentiates them are the features you've been discussing, like air integration. Air integration--that is, measuring your consumption of air--has nothing to do with calculating no-deco time. No relation at all. Measuring air consumption (well, measuring the pressure in your tank) is something your SPG does in a non-AI computer. All that AI really gets you is the convenience a single display to look at, rather than having to look both at a computer AND an SPG. Well, that plus the function mentioned above of computing Air Time Remaining that some people find convenient.
