I don't main a hunter, but I do play one as an alt.
First and foremost, I can't speak for survival or marksman because I haven't tried them yet. I really don't want to play a melee hunter, and I like having a pet so marks is out.
With that being said, I absolutely hate how they butchered Beast Mastery. I took my hunter out for a spin yesterday and was not having fun at all. It felt clunky and boring, like something was seriously missing. I can't quite put my finger on it as of yet, but as it stands right now, I most likely will not be playing my hunter in Legion.
However, with as much as Blizz got wrong with some specs, they absolutely perfected other specs. Unholy DK is an absolute joy to play, as is Feral Druid and Elemental Shaman.
The aspect of the cheetah was most likely removed because buffs were removed in general.