There are two schools of thought there, one that want us to build crit, and the other that say no crit, just +healing and downranking.I'm on your side - I don't see that few +healing power to outweigh +2% crit on Benediction - that is huge! I know crit for healers has lower priority as you can't count on it, but those 2% have to be worth more then + 6 healing power. The BiS lists that I'm working from all have Benediction lasting till AQ too, so you're not alone .
For the other pieces - you are right, that is Vanilla itemisation for you... but by the time you'd be in line to get that stuff in MC, you will have the better stuff already, like you all will be wearing Jindo's Evil Eye before we head to AQ!
Don't theorycraft to the level that I really have an opinion on it. The BiS lists are biased towards the +healing school for the most as far as I can see. It also matter slightly when looking at the priests spec, discipline has more from +crit, and can build that up quite well. While the more pure holy want efficient healing and as little overheal (crits) as possible. I think the crit on Benediction is quite nice, 5 set on T1 is also 2% crit, stack with talents and you're looking at 10-15% crit depending on spell and gear. I also remind many that look at guides that alliance/horde is a thing and you need to talent differently depending on that as well. The guides are more often than not written from a Horde perspective for some reason, don't know why, just number of players perhaps.
But, let's move this to another thread or chat, we're hogging the show here