I (painfully) completed Cistern of Slaughter… it was hard and there was only 2 legendaries into it (i did many run, only finding 7 legendary overall)
I never completed Slaughtertar 3000, I hardly found any legendary (maybe 1? it was last week…)
Now, only 1 wave into slaughter shaft, already 3 legs! 
slaughter 3000 was fun but drops were non exsistant for me compared to slaughter shaft. I haven’t completed the other 2 at all but Slaughter 3000 had 2 decent boss’s in it at the end. Totally going to go do it again if anything just for the challenge.
Careful, slaughter 3000 can glitch and the bosses will be out permanently.
