I still say these things are a mess to use without Ice Floes.
I'm 100% dropping my helm for Norgannon's when 7.1.5 goes live, save for a few aoe bosses. It is pretty insane IMO, you have 5 seconds of casting on the move every 3 fireball-pyro combos.
I'd bet dollars to donuts the belt/helm beats bracers/boots by a country mile. I'm tellin' ya, with the NH testing I've done, those bracers are going to be a serious pain in the ass to use without Ice Floes or boots. Sure, you can Shimmer out, but if you're using RoP (and should be if you have the bracers), Shimmering out of your RoP to get a cast off is going to decrease their value significantly.
The bracers look great on a zero-movement target dummy sim, but they're completely impractical to use in NH on just about any encounter, especially Mythic and double especially when you're learning the fights. Between that and the significantly reduced proc chance these things aren't going to be anywhere near as hot as people hope.