...if he is already diving in different conditions....?
hmmm, I don't see any reference to the type of diving monkman is doing in his original post, so you have me somewhat perplexed.
Personally, I like the Scubapro/Atomic line of regs (read mk20, G250) because of the ease of breathing, adjustability, and reliability in the many different conditions that I dive in regularly. However, Ocean Reef makes a good regulator for their Neptune II full face as well. So, hey, I think it boils down to personal need and preference.
But, then again, monkman was asking about an Arctic reg. So, monk, check out www.usdivers.com, talk to local divers and stores, and do a search on the internet and look on discussion boards. There's a lot of info out there; the reg has been around a long time and is still made.
Just my two cents worth...