Ive been using purified lunar dust and abacus as well. Now I do have heroic bauble now too though Which has been rather life saving to me pvp wise lol But Ive been switching which ones Ive been using back n forth depending on whether or not im healing as holy or disc as well.
If you are raiding in ICC, as I assume, I would recommend Solace + Abacus. The PLD has a substantial amount of spellpower over Solace, but is not as good in the regen department. Healing is so buffed in ICC that stacking spellpower isn't nearly as important as before. In hardmodes, particularly LK & Sindragosa, the regen from solace in unsurpassed. The proc heal from Abacus is clutch, has saved quite a few lives and the heal can crit!