It depends, just be aware that enmity down has a cap of 50, including atma. So if you use Minikin and have four enmity down merits, that's 24 right there. You could only benefit from, at most, 26 enmity down on equipment.
Even then, enmity -50 is pretty drastic and is usually not necessary. Before Abyssea, I rolled with about -30 and it was never a problem. In Abyssea, I just stopped paying attention to it completely. If I pull hate, it won't be off a DD that's for sure, and if hate is on something other than a DD then I actually WANT to pull hate. I'd rather have the monster attacking me than say... a BLM. Hell, I can actually tank pretty well thanks to nearly unlimited MP and tons of fast cast from atmas. I've avoided quite a few wipes by simply kiting or even face-tanking things while the DD's unweaken. (Bukhis comes to mind... that evil bastard)
____________________________Pergatory (Asura, Kupo LS) WHM99 ~ SMN99 ~ DRK99 "If you want to know me, look inside your heart." -Lao Tzu