4% wasn't it? From 10 to 6? With 3 ranks that's from 30% to 18%. Sure the bug fix is nice but couldn't we see how it worked out before they nerfed it?
It's not hard but it has some intricacies. Being aware of serependipity and the CD's of your holy words takes a bit of brain power if you're planning ahead, but overall I'd have to classify it as easy because it doesn't have any positional requirements, has tools for every occasion, and doesn't have any unique mechanics like holy power or that sort of BS to manage. I have a hpala, a resto druid and a priest at 110. I'd say none of them are really that hard.
Disc priest on the other hand is pretty tricky to play well though.