There is no doubt the Hunter encounters in this game were subpar to their predecessors.
I give 3 reasons:
<mark>1. Not enough combat variety.</mark>
Everything was laid at your feet on Requiem (allied distraction, fuel rod gun). Likewise Composer, which was truly the worst due to how tame the combat was. When I read the achievement for killing 2 Hunters with sticky detonator, I was under the impression we would have to fight Hunters in a maze! Instead, it turned into a camp fest.
Furthermore, there was a lack of innovation. They did not have anything new at all to show us and they were far more vulnerable than Reach Hunters.
However, the Shutdown Hunter encounter was spectacularly done. There are many ways to dispatch of the Hunters, such alternative approach is even encouraged (achievement for knocking a Hunter off the ledge). The environment is ideal for melee-only challenges for those brazen enough.
My only disappointment with Shutdown (and this is very minor since most people wouldn’t have heard of such a concept) is how they cannot be led anywhere (like in Halo 1) and how you cannot skip them. I’d love to return with a Banshee, get a Hunter on top, and ferry it to the end of the level. 
<mark>2. No epic music playing.</mark>
Why does the Mantis get it’s theme music but the Hunters don’t? Though I like how Spartan Assault seems to have a remake of the Halo 1 Hunter theme. Hopefully the Hunters will have a theme like that in Halo 5.
<mark>3. Lack of interesting matchups.</mark>
Honestly, I’d have expected them to be accompanied by a bunch of Jackals or Drones (which were unfortunately absent).
I’d have loved to see a Hunter pair vs. a Battlweagon pair…
Their lack of teamwork with the Prometheans (i.e. Watchers did not bother shielding them) made them even more stagnant.