I tanked KJ on my VDH - my main at the time - and with help from legendary could do it fine. As long as I was careful to have spikes plus another CD for every special attack. But if I got distracted and slipped up even once in that long fight, I would die and we would probably wipe. Brewmaster, on the other hand, has ISB up 100% of time and merely has to purify when stagger is high. And this comparison is why Brewmaster is always strong for progression raiding. It's very nature brings much needed stability while the raid team learns new fights. Other tanks may take less total damage, but Brewmaster is least likely to get one-shot and end the fight early.