I still haven't played it, but I'm not liking what I'm seeing in the streams. From what I've seen, only the thrusters seem to be a positive adition. Everything else looks bad.
ADS? Awful. It sucks in any game, but seeing it in Halo is like a kick in the balls. They didn't even bother to add the option to use the classic scope. And of course, it is not purely cosmetic as they said.
Clamber? Just a crutch for bad players. If a players misses a jump they should fall, end of story.
Ground pound? I can't believe they removed crouch jumping to add this filth.
Kill cams? LOL. There better be an option to disable them.
Then there's other things like sprint still being in the game, the sound effects not sounding like Halo at all, the dudebro spartans, the slow movement speed, lack of combat clarity...
IDK, maybe when I play it I end up liking it, maybe a miracle happens and it actually feels like Halo despite all evidence saying otherwise... Halo is the only console FPS I still like, and Halo 5 seems to be a Halo game in name only.

Ogre 2 quitting the beta after just a couple of matches to play Halo CE instead says it all, really.