In the latest push of the PTR these sets are nerfed. For example, my frost set is going from a total of 179 dmg to 145. The fire set is similar. The other changes are negligible, it's mostly just the dmg change. The mage forums are gonna combust from all of the fire mages that are rallying. Frost got affected too, but it looks like mostly fire mages are showing up since they are the biggest dps freaks. Honestly it's not a huge change. The nerf might even be justified, but it's still causing riots because the change came so late that people feel like they got the old bait and switch routine.