Warzone's horribly messy, and Arena's horribly crowded. It's like they didn't realize that increasing map size vertically isn't the same as doing it horizontally. The increased elevation does so little to give you space in matches, so someone's always on top of you. There are a few that aren't too bad (like the removed Orion map), but then you have Fathom (the worst FPS map I can recall playing in my life, especially for Halo), where you're constantly getting jumped.
Warzone's got four canned maps of the same thing, and it's just not fun after long. If enemies were dynamic, bases actually mattered (Legendary Bosses decide basically everything), and the non-Legendary bosses weren't so easy, it would be different. Instead, it's impossible to make a heavy impact in such a large mode, everything is random luck on whose 73rd bullet gets the Legendary kill, and you never get a sense of accomplishment.
But no, my disappointments in Halomaps cant' drive me to the awful life that is BO3. It's just such a bad, illogical game. I can't do CoD anymore when it's just gobs of Aim Assist ans inconsistent physics. Drives me insane.