In your opinion, can you tell me if you felt a difference between the Z2 and B2? looking at them now. Reconsidering this over the T3 since its definitely a lot cheaper. Only reason why I chose the T3 is them selling me that it would last longer
With atomic, the only main differences between the models are the specific materials used. With the t3, you're getting a titanium 1st stage, so it's more resistant to corrosion and a bit lighter, but that's the main advantage you're getting. With the st1, the first stage is stainless steel. For the b2 and lower, it's chrome plated brass. If you're an instructor, diving 2-3 times a day, every day, for years on end, it may last longer. Atomic has longer service intervals on some of their models, but even the base ones last a long time before needing service. Long story short, you're unlikely to wear out any of their models.
Between the z2 and the b2, it's really more comfort features. You get a spinning turret on the b2 and higher for the first stage. The z2 is a 7 port first stage with an axial port. The turret is nice, but other than that, I haven't noticed any difference. The z2 performs great and is what I use most of the time, mainly because my z2 first stage has a yoke and my b2 is din, and that's been appropriate for the diving I've done lately. If I was buying new, I'd probably buy a b2 for the turret.
The ti inflator is totally unnecessary. If I came across one cheap, I'd probably pick it up because I like shiny things, but it's totally unnecessary over the inflator that most bcs come with.
I definitely wouldn't spend a ton of money on a super expensive bcd starting off. I eventually moved to a bp/w, and even that I've reconfigured a couple times.