Kir

I haven't run conclusive tests, but I'm running AM spam with the blue meta helm from the terrorkar guy (the one that costs 20 spirit shards) and it's still a strong contender. I was too impatient and wanted to test out the spec, grabbed it and I'm very happy.

Assuming I've got a shadow priest, which I'm getting whenever it's possible (we put them with healers for naj'entus, for example) it's sustainable enough for any boss fight up to Teron/Kazrogal (I haven't been on any fights further in progression) with chain potting/gemming/etc.. When JoW is gonna be up and I have a shadow priest, I've got plenty of mana and I switch to molten armor and use AP at the beginning (so it can refresh during fight for sure) regardless of CC.

I'm seeing a large increase in damage over using my spellstrike hood. The gem itself is accounting for about a 15% increase in damage. The difference in stats between the blue helm and spellstrike is not 15% of my dps stats.

I don't have 2pc T5 though, so it's hard to say. I want to get a T5 helm and shoulders, as the base stats are good already, and it gives me the option of AP+AB spamming if I've got a plethora of mana (i.e. if JoW is up, which has been hard to convince my guild of how big of a boon it is. Our prot pally tries to keep it up on a lot of fights, but there's still some that we could have it up for that we don't.) . Without 2pc T5, I think the ABx3, AMx1, scorchx1 trickery actually does basically the same DPS. Fully debuffed AB spam with 2pcT5 is more dps then simple AM spam, but hardly 'sustainable' in any way. It still gives a mini burst dps effect if you've got the mana to burn to end the fight. I call it the mage finishing move.

There's another mage in our guild who has 2pc bonus and does the whole AB/AM/scorch rotations. He even does full AB spam on trash. He does more dps then me, but he has also has me quite out-geared and it's not as big of a gap as it should be for his gear. Doing quick and dirty math, I've calculated I'd have higher dps then him with comparable gear, which assumes he is still doing AB/AM/Scorch and I'm just AMing. I don't have TLC or ashtongue trinket at all. Trying hard to get in some karaz runs for the TLC, but the guild is 4 bosses deep in hyjal and BT now, no one really runs karaz anymore. The other mage wants a meta helm to go AM spam too, and I think he'll stay ahead of me if he does, depending on gear, of course.