I've had the "husk" drop a lot, but have never got the crux to drop. I deleted the old raid gear due to vault space, and now I keep getting raid armor and things I previously had deleted. I've been trying to add everything that drops in the raid to my inventory hoping that it will raise my chances of the crux dropping. Crota has very poor drop rates, but the raid is pretty easy solo right now and much funner than it was in a group. So yeah if your decent at PVE and a collector and have most of the other destiny loot, then it might be worth a try. You should be able to run raid with each character in a few hours once you get down the bridge jump.