I have one. They are a nice novelty, but for that kind of money, there are WAY BETTER COMPUTERS.
The Shearwater Predator is light years beyond the OC1 and roughly the same price. The base model is quite a bit cheaper than the OC1 and still WAY better.
A Cochran is better, and cheaper
A Liquidvision is better, and the same price
The New Atom 3.0 is very very similar and cheaper
If it were me, and I couldn't live without air integration, I'd buy the cheap Shearwater and find last years model of the Atom 2.0. and use it in Gauge Mode. Incidentally, you'd have air integration through the Atom, you'd have a very high end Shearwater capable of doing several gasses including helium and oxygen. You'd have some redundancy. You'll never outgrow the Shearwater. And you'd have both computers for what one OC1 costs.
If you are not hell bent on Air Integration, buy a single Shearwater Predator, doesn't matter which one you buy, every one of them are light years beyond the OC1 and they are the best computer on the market.
BTW - I am an Oceanic, Cochran, and Shearwater dealer