ScubaPro MK25 or MK25AF

[Azotino]

No, people are getting freeflows with the finned version MK25 in cold water. I have a dive buddy who finally gave up on his freeflowing MK25s/S600s and got MK17s/G250Vs that haven't given him a bit of trouble.

Cold water....Scubapro the S600 I've seen things you people wouldn't believe.

I remember this one:
S600...."A logical evolution to the legendary G250, this compact and lightweight second stage incorporates numerous patented features such as a chrome plated brass and technopolymer valve housing and a linear high flow air balanced valve. Because of its adjustment possibilities, this second stage adapts to all diving conditions and all diver preferences."............Why they went back with the g250V
Apeks...this is a good one for cold water