I dont see why going for more than 20%holy crit and then the extra 3% from your mage (if you're playing with one) is worth it considering what you're losing in manareg. (the PvE ,,softcap'' people were talking about because of divine aegis was around 30% (+5 from boomkin) if i'm not mistaken and I think thats way too much for pvp)
Yes your games might always or 90% of the time last 2 minutes but the extra 3-4% crit in those 2 minutes I THINK wont be saving you as much as the extra regen will be in the longer games. Crit is a rng stat, might safe you might not - mana reg isn't
I also doubt you'll run into as many cleaves as last season.
I'm going for 4/1, the dagger and one offpiece which will give enough crit imo (or 20%).
I fucking love heavy crit spec/gear for threes and i personally dont worry about my mana regen at all. There was probably like 2% of my matches where it came down to my mana.