In my experience (only got 1600 this season so take it with a grain of salt if you’d like) is that if you are playing double dps in 2s which is what I play, overall spirit beast is the best and whenever I try a different type it never works out.
You could make a case for mortal strike pet, but with double maledicts trinket you don’t really the debuff and your pet dispel and heal are sorely missed if you don’t have a dispel on your team. The run speed from cunning is nice, but without it you can already kite pretty much anyone if it’s 1v1 and if you are getting double teamed, even with cunning it’s almost impossible to outrun 2 melee on you despite having extra run speed and root break. Also, don’t forget that a spirit beast also gives you a 20% dmg reduction ability.
As for the hunters using Hati, it’s just a skin of a spirit beast and people just seem to really like it. I use the ghost porcupine from pandaria, but it does the exact same thing as all spirit beasts.