Spec comparison of Atomic regs here:All Atomics breathe the same so if the cost of the T3 is a factor - look at the B2 or ST1. since they have the same functionality (swivel hose, turret) at a lower cost. All 3 models have an all Ti 2nd stage.
Even A Z3(not Z2) has the 2nd stage swivel - just not the turret. Both stages made of Zirconium plated brass.
I've owned a B1, Z1 and T2 so I've used much of their line.
A lot of the important B2 internals are Ti also - just not the 1st stage body which is chrome/brass..
Every model has the same factory recommended service interval.
If I was buying now- I'd buy an ST1 as the corrosion resistance is all but the same.
The extra $750 buys a better octo. Or their SS1 Octo/Inflator which breathes the same as their other models.
Also a B2 is $1000 less...
Atomic Aquatics Regulator Specifications
Service interval reco is here - T3 can go 3 years/300 dives vs 2 years/300 dives for others - so a slight advantage if you don’t get in 150 dives a year?
https://www.atomicaquatics.com/reg_manual.pdf