I am actually really liking Frost's new mastery. By hitting the 9768 (ish...I forget the exact number) hast value for my bombs, I am finding that my arcane and frost numbers are not too different at all. It really depends on the fight. I am honestly very happy that blizz gave us the option to juggle two specs like this.
Which fights are you finding to be frost's or arcane's fight? BTW, this isn't a "which is better spec" garbage thread. After playing all three specs, I can say they are all so similar it doesn't really warrant a thread. This is a, "what fight are you enjoying with your spec" thread.
I am not the best at positioning, so on some fights like thok, Malkorok, and the shamans- I pretty much will have to be frost.