Extremely easy breathing especially when coupled with a balanced 2nd stage. I use them for both recreational & technical diving. They will give me all the air I could ever need. As for cold water,... probably not the best suited. Because they are a high performance regulator capable of delivering a lot of air, they can sometimes tend to freeze up easily. I commonly dive them in 42 degree water & out of 200+ dives in that cold water, have only had 1 feeze- up & free flow. At that time, I was at 95 ft in the local quarry. The water was 42 degrees below 60 ft. I was in double cylinders, breathing off my secondary regulator & my primary was shut down (for a drill) with great difficulty. I accidently tapped the purge button when I released my wing to help me reach the valve. I breathed off the freeflowing regulator to the surface (with double cylinders I had plenty of air to make it). That little tap was all that it took. Like I said, although, perhaps not the best for cold water environments, they can be dove in cold water. The big thing is to be prepared for when it does freeze up & be able to deal with it safely. It will not be a matter of "if" it happens, it will be "when" it happens.
