Terkel,
(from my experience) Whatever people say about Scubapro regs, they are nice regs. I know several people with them that have no problem in cold water and absolutely love them, however, I know quite a few that have had problems with Scubapro regs. I suspect that this is down to one of two things, either the rate of air consumption (the faster you use air the greater the temp change), or a setup problem.
From the people I know, you either have a problem reg, or a super reg. Having it serviced has in many cases not helped. So, I suspect that air consumption has something to do with free flowing problems.
Please remember, this is just the conclusions I have drawn from having seen other people in diving clubs. I could easily be wrong as I tend to look for scubapro problems, and I am biased towards Apeks.
Jon T