Priest end-game stuff.

[Alarick]

The +crit% items are mostly useless for priests. The heals of a priest are designed to be effective without taking crits into account. Thus, a crit frequently is just wasted.

It may be nice to go with +healing items, but keep in mind how much you will be sacrificing in terms of stats and mana. One of the more commonly used spells, Flash Heal, apparently gets about 40% of the listed bonus to its healing amount because of the faster casting time. The only spell that gets the full amount is Greater Heal, and its applications are limited.

I'm not really sure how the whole +healing and +damage thing will turn out in the very long run of the game. Blizzard seems to think that they will be the equivalent to adding DPS for weapons. However, with the nature of PvP, quick spells are what needs to be cast as much as possible, and this limits the use of the enhancements. On top of that, so far all items I've seen sacrifice stats for +damage or +healing, while weapon DPS goes up without sacrifice to any stats.

It's a problem that will have to be figured out soon. Most likely, by the time raids start clearing Blackwing Lair regularly like they are with Molton Core now, there will need to be some balance figured out for the stagnating spell damage and healing. If not, PvP will degenerate even more and melee fighters will have an even bigger edge on casters.

I got aa bit off topic there, so to get back on I reiterate: be careful about going +healing, because the added healing is limited by the spells, and the stats you will lose (particularly with the current setup of armor) can easily be far worse than the added healing.