Since you decided to, as a boomkin, make your way to the shadow forums and have a discussion, let's have one. I always like when people post things like this and also include something in their signature so I can find them. I'm assuming you're the guild on 10 man guild on Skullcrusher that finished top 900 world/top 300 US and just killed Lei Shen 2 weeks ago, correct?
I'm also going to assume that this is the spriest in your guild: http://raidbots.com/epeenbot/us/skul...C3%A9%C3%A9ky/
While your logs look alright as a boomkin, the majority of your DPS parse awfully low, so it may seem that your spriest is good. HOWEVER, the fact of the matter is that your spriest is not that great and neither is the rest of your DPS, judging by the logs I found.
I dunno, sounds like user error to me.