Why the hell is best in bag telling me to use a nerfed 4 set and to stack haste as a holy pally? Somethings not right here. It should be crit to 50% and then Mastery after. Haste is shit for our class.
Can you post your export string from the addon so that we can see your BiB?
When I look at the gearing strategy:
http://www.askmrrobot.com/wow/simulator/report/b86f9506f02b4ab1919f89f6d307b1aa?weights=true
I see sets with a lot of Crit, and then decent amounts of Haste/Mastery simulating best.
It is not clear to me why haste would be categorically bad for holy paladins. Holy Paladins are hard-casting a lot of single target heals, so haste would be a relatively good stat if you are not mana-limited.