The Campaign was very forgettable with no real standout missions. Like how Halo 3 had the one where you take down the 2 crabs and Reach had the one where you fly around in space. And well nearly every mission in CE was great.
Spartan Ops has no replay value whatsoever. Once you get the achievements there is no reason to ever play them again.
The ranking system is terrible. What is the point of copying the way CoD does it if you are going to give us a xp cap and a permanent hard cap? That is obviously going to drive a lot of people away once they hit level 130 and wonder what they are playing for.
The servers are just bad. Now Reach had its problems but not even half this bad. I have honestly had less connection issues with Black Ops 2 than Halo 4 and I have had both since launch day.
Join in progress sucks. I’m so tired of being put into games on a losing team in slayer with my team down 450 to 180 or a CTF game down 4 to 1.
There are only 10 maps on disc and most of them are just bad. How many times do I have to play Haven, Exile, and Ragnarok because every other map is so bad nobody will ever vote for them.
And finally the playlists or should I say lack of playlists really makes the mp get stale fast. Everything I loved from Reach like Grifball, Rumble Pit, Big Team Objective and more are nowhere to be found.
This is just my honest opinions as a long time Halo fan.