Sorry I've been away. Was on vacation and then work ate my life.
Anyway. Now that we have a (relatively) stable group, we've been working on Sindy for two weeks now, last night was our first serious series of attempts and we got her to ~10% on our best try.
Previously, Icy Grip was the bane of our raids, people would die and I'd gnash my teeth but after much thought, I changed our positioning to hold Sindy horizontal to the stairs and have people just DPS and heal from the stairs things worked out very well. It gave people a very specific point to run towards (up the stairs) and dropping blocks on the stairs makes Ice Bomb dodging trivial.
So, ever since the first attempt last night, I saw that Phase 1 and 2 are down rock solid, we barely ever lost a person to Icy Grip, and we got her into Phase 3 right after her 3rd air phase with 3 full time healers.
But people seem to panic on phase 3.
We manage to hold it together for about 2 or 3 blocks, I assigned 2 melee burn 'em down, people clipped their debuffs, tank swaps happened whenever the other tank's debuff dropped, and then either an Icy Grip or a misplaced block would disrupt the process and then we'd fall behind and never catch up to switching to the boss because blocks start coming too soon and then, we hit enrage with anywhere from 15% - 20% left to go.
Our best attempt got her to 14% or so, I think, which was still a solid million and a half hit points.
I think our current strat will work, we just need to spend a little bit more time on her and focus our energy.
On a side-note, I'm especially pleased with the guild's membership right now. Lots of friends, both old and new, and only one or two trouble spots that I think will settle down soon. It's good to be in such company in pre-Cata days.