Ah, I see. There are a few thoughts rattling around in my head.
I guess that underlying my question are these thoughts- one, I have been considering the Aqualung i300 (now i300c) and the Aqualung i500. If Oceanic offers the same computer with a different name on it (plus the second algorithm) then the Oceanic brand might be the better choice. Most of my computers are older, some I haven't dove with as they came as parts of other deals. I think I would like to get a new computer with some room to grow. (I love the specs of the Shearwater Perdix, but can't make the investment yet. The Peregrine would work, but I prefer the user changeable battery, and having the compass would be nice. So, these would be a few years out.) Now, having mentioned "room to grow"- I have a number of specialties, including night, ice, deep, enriched air, wreck... I can see myself taking an intro to tech/deco type
With regards to regulators- this comes from a couple different directions, as well. One, I was reminded this fall just how expensive it is to have regulators serviced. I have one thread where I asked about manuals and parts to do my own (I haven't done so yet) but if there are regulators that are easy to maintain, and some brands of those regulators are less expensive than others, than I might look at replacing what I have for future savings. I don't recall which brand(s), but I think HOG or Edge maybe, are fairly (relative term, I know) to work on, and it is encouraged rather than discouraged, as done by some manufacturers. And, from the little looking I did, the initial investment wasn't as high as some others. Another thread recently had discussion whether it was better to buy regs, use them for a couple years, then replace them rather than have them serviced, due to the high cost. I can see potential merit in that situation, as well, though it's not my preferred method at this time.
I currently have a mix of regulators- Apex, Aqualung (both circa 2000) as well as a couple sets of Sherwoods and a Mares and Oceanic set, none newer than 10 years or so.
Where I live in Maine, I am thinking I should have a sealed first stage, but I haven't gone ice diving since the class over 20 years ago, so I probably don't need the Sherwood Blizzards that I have. I had a Dacor Extreme Ice regulator back when I took that class.
So, in my mind, I was envisioning lists that said that Company X's model ABC is the same as Company Y's model EFG, for however many entries as people could come up with, for dive computers and regulators.
Perhaps I had a simplistic view. :-O