Yup, it's the best I have used so far. The ice line and the normal box look and feel like the same stuff. I have asked around and been told it is the same stuff too...
I have one reel with #10 duracast and it doesn't ice up much if at all. I have another 2 reels with #6 nonofil and they do ice up a bit. I have found out that you need to put something on the spool to keep the line from slipping if using a metal spool. it shrinks when cold so having tape or something for the line to grip to helps.
So far, I'm happy with both lines but i think if I needed to respool a reel right now it would be with the duracast. I got a real good deal on it from Phil last week too! (etackle.ca)