Flakey raiders suck.
The Vodka naxx-25 died mostly because raiders couldn't be bothered to show up when they said they would, and because the whole healing section ninja-quit like Grexis did to you.
I was subbing for Steelshield as DPS. I've been excited about the prospect of making Troa ret since seeing Seel take advantage of the OP 2-piece bonus. Sure it'll get nerfed... so I want in on it before that! Anyhow, at raid time, I suddenly was told I was prot because their pally tank didn't show up, and had to argue really hard to get to roll on ret gear drops (yay, got two!). Then they replaced my DPS slot with a different plate DPS. I probably wouldn't have minded so much had they bothered to ask rather than command...and that it was the second raid in a row to pull that exact stunt (DPS, no wait tank, also you can't roll!) on me.
But on the bright side... you guys downed a new boss!