First, to the OP -- An excellent guide, with a lot of information that I didn't know and am glad to be aware of now.
Second, my bit about stone tanks:
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don't forget the stone tanks

I know because of a time where the whole team wiped with the exception of the stone tank in granite armor, took a lot of time for the tank to wipe the cyst but got it eventually.
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I've been running a stone tank, and there's nothing I have to fear from a cyst. Nictus simply can't pierce granite's defenses, and the cyst's explosion is reduced enough by my resists to be ignorable.
That being said, charging has had a high success rate with low debt. Out of at least ten cysts, I'd say we've managed six with no deaths whatsoever, one with a near team-wipe due to aggroing not just one but two groups of enemies at once (Two PBs on the team sacrificed themselves to take the crystal to about 1/10th life, a scrapper barely escaped with his life, and I managed to kill it with a fulcrum shift that our /kin did right before he fell), and the last three with only one or two deaths due to either a boss escaping my taunt (I hate the aggro cap sometimes) or people being too near the cyst when it exploded.
So, another viable strategy (With no claims to being safer, I'd say it's riskier but works reasonably well): Everyone targets the cyst, a tank goes in first and throws taunt/taunt aura around to pull all possible enemies onto himself (Targetting the normal spawns first, as the spawned nictus seem to do less damage) and then all the melee allies retreat as the cyst gets weak. This does require a tank that can withstand aggro cap abuse levels for the duration of the cyst's life, so a tanker that can perform that is required. One person using a nuke early to clear large amounts of minions can greatly aid the tank in capturing the most dangerous aggro. For the most part, you'll escape without debt to anyone involved if they're smart enough to pull back when the cyst is about to die.