Well, from 70-72 I think I lost about 3% resi on my DK.
As for other stats I can get as high as 82% haste as frost, so I think that's fine.
Anyway I haven't done the total math cause I just thought it was smart to go 72 for engi helm.
As 72 people miss you more often with spells and hits though, so I guess that's a good thing as well...
And Vase, I love double niff frost in both BGs and arena, and I can't see why it still wouldn't be fun with 70 weps, just use a little more howling.
I guess some will argue that blood is better, but I don't really love it, some do... so... I guess you can just try it out!