Thank you everyone for all of your amazing input. I am looking closely at the following regs. Any additional input woudl be helpful.
- SP: MK 25, MK 11, MK 19 - Trying to understanding how the MK 19 fits into these?
- Atomic: B2, Z2/Z3, or maybe even T3 - Trying to understand the differences / tradeoffs of B2 vs Z2/Z3? Realize T3 is probably an unnecessary splurge.
- AL: Like the products but not clear what the differentiators / value proposition is of the many lines: Legend vs Mikron vs Titan vs Helix. They do seem to be quite heavy.
@buddhasummer covered SP.
I don't know about AL.
Atomic:
All their regs are the same design (so, they all breathe great!). The differences are in the materials used.
The Z2 is a 1st stage made of chrome-over-brass - like almost every other 1st stage on the market. The 1st stage does not have a swivel turret, but it does have a Low Pressure port on the bottom. Thus, it offers ideal hose routing for single tank use (unlike 1st stages that do not have a LP port on the bottom). The Z2 2nd stage is also the same materials virtually all other 2nd stages are made out of. The Z2 is an EXCELLENT reg and an EXCELLENT value in the market.
The Z3 is the Z2 with an Atomic ComfortSwivel on the connection between the LP hose and the 2nd stage.
The B2 is the same 1st stage as the Z2/Z3 except that it has a swivel turret. The B2 2nd stage is the same as the Z3, but with some internal parts being titanium, for slightly lighter weight and better corrosion resistance.
The T3 is a solid titanium 1st stage, making it very light and virtually corrosion-proof. It's still the same design and works the same as the Z2 and B2 1st stages. The Z series 1st stages are the only ones with a non-swivel turret. All the other Atomic 1st stages have swivel turrets. But, they ALL have a LP port on the bottom. The T3 2nd stage is the same as the B2. I.e. titanium internals.
Atomic also has the ST1, which is the same as the B2 and T3, except the 1st stage is solid stainless steel. So, it has the corrosion resistance of the T3, but not the light weight. The 2nd stage has titanium internals, like the B2 and T3.
Atomic also has the M1. This is their reg intended for technical divers. It has the same 1st stage as the B2. I.e. chrome-over-brass, with a swivel turret. The 2nd stage is the same as the Z2 - i.e. not titanium internals. The M1 2nd stage has a wider exhaust tee on the bottom, to push the exhaust bubbles further from the diver's face. It has a small heat sink where the LP hose connects to the 2nd stage, to make it a little better in cold water. And it has a different purge cover on the front, to make it a little less likely to give a freeflow when facing into a current, as well as making it able to take off (the purge cover) under water, in case you need to get trash/sand/rocks out from in between the purge cover and diaphragm (e.g. during a cave dive).
As I said at the start, all the Atomic regs are the same design. They all breathe the same. They are just different, mainly, in the materials. You choose whether you want to pay extra for lighter weight, better corrosion resistance, or both. The Z2 is their least expensive reg set and they breathe just as well as the T3. And they are the same basic weight and same corrosion resistance as other regs (like a SP Mk19/G260). The other Atomic regs are just "better", by offering "more" in the same design.
And, most of the Atomic regs come environmentally sealed. The Z2/Z3 can be purchased sealed or unsealed. And, something I think is also nice, you can buy the Z2 or Z3 unsealed and then have it sealed later if you want as well as having it upgraded to a swivel turret later (making it the same as a B2), if you want.
Personally, I would not buy the Z3. The only thing it has over the Z2 is the Atomic ComfortSwivel on the hose. But, that hose is 32" long. Too long (in my opinion) for a primary reg hose and too short for an octo hose. And the swivel is permanently attached to the hose. So, I would buy the Z2 and put my preferred length of hose on it - with an aftermarket swivel, if desired. (which is what I did, when I had a set of Z2 regs for single tank)
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