If you don't raid or do mythics, it really isn't going to matter. You could probably keep using Animal Companion, honestly. Killer Instinct is a better choice for most situations, though.
I agree. All my alt hunters run Animal Companion as they don't do anything beyond world content and at best, the occasional world boss. I just like having a second pet of my choosing.
Killer Instinct is the choice for raiding and mythic +. Dire Beast might be a choice as well if you feel AC is making things difficult for you, but you aren't doing content that really benefits from an execute-type talent.