The red sockets in your pants and shoulders need to be red gems. Replace your blue gems with Purified Demonseye (20 int/20 spirit). NEVER use pure blue or yellow gems.
I'd change the mastery->spirit reforge on your staff to crit->spirit. I know it's a drop in spirit, but you shouldn't really notice it. If you seem to be having serious mana issues, replace the Power Torrent enchant with Heartsong.
Your cloak should have the Greater Intellect enchant instead of Greater Critical Strike. Crit is a poor Holy stat.
All those missing gems and enchants add up! Once you fix that you should see a nice boost in throughput. Stacking haste is fine and dandy for LFR, but if you intend to transition to normal mode raids, you might want to increase your mastery a little bit.
You might want to respec to max out the Heavenly Voice talent. It's a big boost to your raid CD. I'd pull the points out of Surge of Light, Veiled Shadows, or Darkness to do it.
The Glyph of PW:S made me scratch my head. As holy, you should never use PW:S unless you need to apply Body and Soul to a player, which is very rare in DS. I'd replace it with Glyph of Renew, personally. Also, I'd drop Glyph of Fade or Glyph of Dispel Magic for Glyph of Prayer of Mending.
Do you have a WoL to show your healing breakdown? If you don't have that, can you describe it? As in, what Chakra do you use, do you keep PoM on CD, what spell do you use the most, are you doing a lot of overhealing, etc.? Granted a lot of the spell selection is dependent on the encounter and who your fellow healers are. LFR is probably not the best indicator of skill as it is a snipe fest -- if you are experiencing low performance on the meters it could be the other healers are sniping heals from you and there is little heal.
I hope this helps!