We got so fucking cockblocked on ToGC beasts, and have never been able to kill them. The closest was a near-perfect run over a month ago that saw us on Icehowl right as the last Jormungar went down. Then someone got hit by Icehowl's charge and we wiped.
I'm pretty sure we could get Beasts now that we're even better geared, but again, no one really cares. All the gear's going out the shitter come 3.3 anyway, and most of us are just interested in seeing the content (which is effectively done once you kill normal Anub 25, which we did on the first night he showed up, like many guilds), and we dig interesting hard modes, like most of Ulduar's. The fucking ToC hard modes are just the same fights with bigger numbers (save a few exceptions, like having to kill Jaraxxus' demon gates). That's fucking boring and, frankly, the numbers were just too high.
I don't know very much about tanking, but the problem I perceived seems to be described pretty well in the blue post that discusses Chill of the Throne. That's exactly how our tank health behaved. No hits for 10-20 seconds, then spiky damage that killed them in a 1-2 second window. You basically have to keep pouring heals on them during the avoidance period or they're dead when the spike damage hits. That's not fun, it's fucking brutally annoying.