Sorry If this has been mentioned but:
Team slayer maps that are more VARIED in size/play type.
In Halo reach almost all maps within the team slayer playlist allow the majority of kills to be from grenade spam, shotgun/sword.
The only exceptions being if a fight went multi layered in sword base/countdown (usually not that case) and powerhouse/boardwalk.
Asylum/reflection are well balanced (but a remake!) and the anniversary/dlc maps were in a separate playlist altogether.
The then introduced maps through forge are usually similar sizes, mostly small corridors made for a lot grenade spam in MOST games.
The amount of spawn killing has a seasoned halo player (2-reach) fed up as it only takes two DMr weilders to keep a whole team pinned on the cage/pinnacle.
My plea is to add some sized maps to reach to balance out these levels. I still love sword base, but just do not feel the game type changing much between maps! And find myself leaving often for invasion/big team, even though my favorite is the 4x4 slayer!
Thank you to anyone who reads and adds their two cents
ALPHAMALECAT