Another quick question since y'all have been so helpful: my current computer is a Mares Puck Pro+, so would the iX3M2 Pro algorithm would be more or less conservative than the Mares (assuming RGBM) algorithm?
It would be hard to know for sure since RGBM and its various implementations are proprietary. But likely there are settings on each computer that match fairly closely.
Since I'm not a fan of the bubble models (they are good, but I think the modern Haldane models are better), you should probably rely on someone else for the answer to this.
Maybe @scubadada or @BoltSnap can give a definitive answer?
I bought my Ratio iX3M Tech+ circa 2017 (version 1) and I already had Suunto Vyper Air (with RGBM) also at the time. Although my memory is rather foggy since it has been so long since I compared them, here is what I remember based on wearing both computers at the same time u/w:
1. The Ratio is generally more liberal than the Suunto (RGBM) but with adjustment of the GF's, can be made to be more conservative. If you get the iX3M Pro v2 (without custom GF), it will still be more liberal than any RGBM dive computer at its default settings (most liberal) but can be made more conservative by adjusting the conservatism factor. Ratio's computer offers you more flexibility and options the RGBM doesn't.
2. Suunto RGBM dive computer becomes even more conservative as you do more dives and more days of diving. I did a liveaboard with 4 dives a day a while back and by the time I got to the 3rd day, the Suunto has requiring me to do a deco stop for every dive.
In short, Ratio's dive computers can be set to be considerably more liberal than the RGBM in Suunto (and Mares) and can be made to be more conservative also. The Ratio is a more versatile and flexible dive computer in a broader sense than the Suunto RGBM dive computer.
Now I don't use the Suunto with its RGBM at all. I have it as a spare that I haven't used at all for few years. I use it as a loaner to my students. I got a Scubapro A2 a year ago that I use with the Ratio. The Scubapro A2 is somewhere between the Ratio and the Suunto in terms of conservatism without the annoying lockouts of the Suunto. I wouldn't buy the A2 again since the battery is dealer replaceable and not user replaceable.
NOTE: the Scubapro A2 is a watch/dive computer that you can wear all day long as a watch.
I hope this answers your question. I know that I don't have more specifics but this is all that I remember now