Frost resistance, like all resistance, caps out at 5 * caster level (Sapphiron counting as a level 63 since Boss mobs are player level +3) which means 315 frost resistance is the highest effective number you can reach. Why would up to 350 FR be beneficial?
With Frost Aura ticking every 1s, like it did on PTR, you would need closer to 200 from gear. Now when it's every 2s you can cut out a whole lvl worth of resistance. It's a healer and coordination check fight, where they will go oom at one point or the other. If you go in with bad healers you won't finish the fight no matter how much Frost Res you stack. Stacking too much resistance means the dps will be equally worse, making the fight longer for the healers.This is a progression wall boss, not a loot pinata.
Is resist a thing all of a sudden? I thought AQ proved it wasn't anymore.
No more than 100FR will be necessary if players are decent. I'm a part of one of the best GDKP groups in the entire game and this is the research the leadership has come to, and I have also found to be true.
I am going to attempt to write an extension to this to help clarify the lacking and misinformation for users so they know what items to shop for.
You missed the FR neck from the Water Elemental Invasion event in Winterspring,Rogues can use it still for the FR.Tempestria's Frozen Necklace
350 Frost res..? resist Cap is like 315 and our guild is doing 80 for healers, 100 for ranged and 150-200 for melee.