I am in a smaller guild of about ~50 players or so, and due to some attendence issues we are currently working on Sindragosa in ICC 10. After Wiping a good amount last night around 10%, I have come to the conclusion that the transistions when the tanks move to reset their stacks are our problem. This is due to a few things that go wrong during that period. Perfection of that phase comes with time though, and that was the first week of shots at her. My question however involves frost resist gear. I keep hearing that even a small amount of frost resist gear can make that last phase Much easier. Since I know the problem is when people are going to reset stacks, limiting the ammount of times they have to will fix this problem and increase the amount of DPS uptime on the boss. With that being said, how much frost resist would people need to be helpful and have a noticable effect.
TL;DR How much Frost resistance gear does it take to make an impact in the Third Phase?