Well first, Fleshcraft is not the only perk. With Marileth, you get a 15% health shield upon reaching half HP, and it’s only on a 30 second cooldown. So that’s nice.
Fleshcraft can be used during Turtle, so you always get a full channel. You can also use it the same way a Shaman uses grounding totem, to nulify incoming CCs. I’ve absorbed HoJ, blind and kidney shot with it and it’s great.
Besides, it also heals you for a bit thanks again to Final form.
As for Death chakrams, with my 202 gear and burst cooldowns, it ticks for about 1400, 7 times. It’s pretty awesome combined with Crows for some big pressure every minute.
Don’t forget there’s a conduit to increase its damage by 10%, and in the next patch they’re buffing it by 15% again.