Primal Rage is completely useless in most raids. The likelihood that you won’t have any mages or shamans is really quite low. As for the leech, no, having another DR cooldown is substantially stronger than the leech. Leech isn’t really bad, but it too often is either wasted in overhealing or simply insufficiently strong.
As for “the small on demand heal”, Spirit Mend currently heals me for over 30% of my hunter’s HP over the duration (~7.5% initial, plus a smidge under 5% per tick for 5 ticks). On a 30s cooldown, and it being able to be targeted on other raid members, it’s exceptionally strong right now.
Now, the AP coefficients are a bit difficult to read atm, but it does look like it’s being nerfed by 67%, which would put it around a 10-11% heal. That puts it more in check, I think, but still probably quite strong.
Looking at my hunter (currently ~450, he’s definitely an alt), he has ~450k HP raid-buffed, and deals roughly 40k HP on a straight single-target fight. Predator’s Thirst thus is ~4k HPS, provided I’m always under max HP, or about 0.85% max HP per second. Currently, that’s at most about 25% HP per 30s. It falls far short of Spirit Mend right now, especially since Spirit Mend is burst healing and happens when you need it (and can be cast on others). Yes, Aspect of the Beast can affect that balance, but the burst healing, on-demand, and targeted benefits of SM still place it considerably ahead, imo. Add in Survival of the Fittest for on-demand DR and bonus HP for helping keep you alive, and it’s pretty clear, at least to me, that spirit beasts win by a mile in raiding content right now (unless you’re in that rare situation where you don’t have another source of lust).
Now, in SL, SM is down to a ~11% heal. It’s still on-demand, burst, and targeted, and you still get Survival of the Fittest, which in my mind still makes SM likely better than a Ferocity pet. Lust being highly redundant in a raid setting really hampers Ferocity pets there. I can definitely see arguments for it in 5-man settings, especially with the significant nerf to drums, but in a raid spirit beasts are likely to still be the most logical option for BM.