Super High Performance Regs

[rescuediver009]

Yep, the ATX100 & ATX200 come with 1/2".

Actually you can add the ATX50DST and ATX40DST to that list. The only exceptions are the ATX50DS4, and the AT20. I know that they are larger diameter but if you look into the end of the hose you can see that it tapers right away. I am sure that this is still superior to the 3/8" port however not as much as it may seem.

On the topic of metal vs plastic 2nd stage housings, things get different as water temps approach & fall below the freezing point.
My experience has been that metal is less likely to frost up above the freezing point, but more likely to freeze up when the water temps get below freezing.

If you are diving under the ice, the general principle is to keep the parts with the moving air under the water. If they come out they will freeze. And the whole iea of the metal, it would behave like your tongue on a flagpole (freeze instantly) if wet above the water. Otherwise it also works the opposite under the water. It conducts the warmth of your breath to prevent freezing.

 

[Bob3]

...It conducts the warmth of your breath to prevent freezing.

Yep, until the water temps get below freezing, when your breath condensing inside the metal housing forms a block of ice inside. Plastic housings are insulated a bit from that & the heat from exhaled breath keeps things thawed.
If it's cold enough, (like the first couple weeks in February with air temps to 40 below without the wind chill), in a fast moving river or heavy surge on the Great Lakes, the water temps can get to 28°f.
Happy to be retired from that stuff now.