When to break the T14 set bonuses

With tier 15 just around the corner I was wondering how much of an upgrade a tier 15 piece needs to be before it becomes worth breaking the tier 14 4 and 2 piece set bonusses? To make this discussion more concrete, I currently have the 4 piece bonus using normal mode legs and hands and raid finder head and shoulders.

When upgrading a 483 (0/2) Tier 14 helmet to the 522 Tier 15 helmet, you gain the following stats:

+712 stamina
+734 strength
+568 Armor
+1104 mastery
+240 expertise
-1004 parry
-240 stamina socket bonus
+180 parry socket bonus

I wouldn't think twice about breaking either set bonus for that upgrade. Especially if you'd get the 2set T15.

If you're not 2/2 Heroic T14 right now, just break the set bonuses and pick up the 522 gear. Personally, I probably won't pick up any tier for a while, because the bonuses are rather lackluster for me.

Thanks for the advice guys. I'm certainly not close to heroic modes so I'll just take upgrades as they come.