Dr. Lecter
Contributor
How significant is their cold water capability over sealed diaphrams? A rubber seal filled with christolube sounds quick fix solution to cold water diving. No?
As opposed to a thin silicone diaphram, which isn't a quick fix? I think the more completely sealed nature of the dry seal is what makes the sealing approach somewhat better than the goo-seal approach of the sealed piston regs. Though the diaphrams are surely cheaper and easier to replace.
Moving from the 1st to the 2nd stage, I was interested to learn that one of the reasons AA insisted on a brass/zirconium valve tube on the M1s was its better heat transfer properties. Between that and the sealed 1st stage, I'm happy with my M1s for any water I plan to enter, even if its in the low 40s/high 30s. Ice diving is not one of my aspriations... if it was, I'd look at the issue more closely and would at least consider putting my M1 2nds on my DS4 1sts.