Atomics T3 is all titanium and very expensive. The B2 and the Z2 are not titanium. A sealed B2 or a sealed M1 would work well for the cold. Around here most of the cold water divers use the Apeks XTX 200. Atomic advertised their M1 for cold water. I have had no issues with relatively cold water 39 degrees with the Atomic M1, Apeks XTX200 and ScubaPro Mk19evo /G260
Thank you for your answer Shabaday, the reason I asked was I seen somewhere on this forum that titanium second stage can freeze in very cold water (B2 is titanium made same as T2). I like B2 because it has a swivel, but I suppose I can get M1 and just a hose of B2 with a swivel.
XDeep been recalled last year but I suppose it’s a good thing, new equipment this year should fix whichever problem they had.