Whats the consensus CR for Blood DK Tanking?

[TricksAnthem]

I'm currently using Necrophilia and it seems to be working fine, but I wanted to move onto heroic and mythic and was wondering which CR is currently the best for high end raiding for blood dks.

 

[Macatho]

TuanHA gives me good results.
For example 18k HREQ/S on kromog.