I would assume the one that makes your bleeds tick 25% faster will help quite a bit: basically, if you Rip a large number of targets via Primal Wrath, you get a significantly higher amount of your DOT damage to tick before overwriting it.
The one giving you free bites from Rip ticks might also be nice in AoE, depending on how the proc chance scales if you have multiple rips active.
The one that boosts your affinity and gives you 15sec of HotW once per minute also sounds like it could be quite powerful.
To be honest, I don’t really understand the gloom about the (Feral) legendaries (and I generally like to moan a lot about the state of Feral!). At least at first glance I think they could be quite powerful.
/Add: Man, Feral’s melee range is going to be insane! Double Astral Affinity effect 