In reply to JayPee630:
I think there is a bit of confusion surrounding Alpha and Primaloft.
Blackreaver got it right, tops using Alpha are more of a fleece replacement and they do seem to breath/wick better than Primaloft. It would appear that this is because of the inner mesh type lining and the structure of Alpha. Primaloft tends to consist of interwoven strands, which trap heat better but possibly slows down the movement of moisture. Alpha only has strands running from inner fabric to outer fabric (simplified and possibly not entirely accurate description
. This helps move liquid away from skin quicker and does not trap as much moist warm air. Of course it is not as warm as Primaloft...but it's not supposed to be. It's an active insulation as opposed to static insulation.
Every one I've spoken to, thinks it's bloody fantastic. Used in Iceland doing Sprengisandur route (not myself) and wide variety of U.K. winter conditions.
I think Alpha clothing is ideal cold weather active insulation, much better than light Primaloft clothing. The weather resistance so far, newish Strata hoody,is awesome. Functions well as an outer or inner layer.
Really curious to see what the brands do with it. I think it's potentially game changer if used in well designed garments. I should mention I work in the retail side of the Outdoor industry, no affiliation to any manufacturer.