Is Atomic suitable for tech diving (just for future proofing)? it doesn't seem like any of the tech divers I know use atomic (mostly apeks, dive rite, etc.) I assume T3 is not suitable for tech because titanium is not good with high % O2?
Most tech divers are cheap. Or, maybe I should say, very budget-conscious, since it's already so expensive.
If you are paying list price for all options, the Dive Rite regs are really hard to beat. 100% O2 compatibility out of the box. Nice, compact 1st stage with a sealed diaphragm design and a swivel turret with a bottom port. 2nds are fully adjustable and reversible (i.e. can have the LP hose coming off the left side of the 2nd stage, if you want to).
And they're Dive Rite. A solid company that has been around a while. And, because of that, not too hard to find local servicing for.
Before I got on a shop bandwagon, I was using Dive Rite XT regs for my doubles and very happy with them. Once I got on the shop bandwagon and bought some ScubaPro regs, the DRs became my deco regs and they work great for that. Compact, so they aren't obnoxious against my side, and a swivel turret for nice hose routing when the deco reg is stowed and deployed.
At list price, about the only thing I can think of that competes with them for tech use is the Deep6 Signature regs.
Overseas, it's probably a little different because of the different relative costs of things over there.
Regardless, the tech-suitable regs from Atomic are significantly more expensive. That would be my guess on why they aren't as popular among tech divers as some other brands. Of the people who do use them for tech, I bet a LOT of them did not pay full list price for them.