Originally Posted by
SwiftExE
Only way to know is if you sim yourself. However, I can say that if you're geared (like around heroic Nighthold ilvl), I'd say there's probably a 90% chance that helm+cloak is going to be inferior to another combo of legends just because of the stat loss (like you said). Our current tier pieces just have trash statting all around (except for the helm...but we wear the legendary one so thanks blizz haha). I don't remember off the top of my head, but I think I recall Tomb tier having better stats, which might end up making helm+cloak more viable.
Right now, my best combo is actually helm+bracers (recently overtook helm+boots), so it just goes to show how you can't simply rely on a legendary "tier list" to determine what you wear. You just gotta sim it yourself since everyone's gear and stat situation is different. I'm currently crossing my fingers for Prydaz, as I'm guessing it will perform better than the bracers.