Keep in mind I mainly play private matches with friends and bots, although I have played a lot of public games to get the feel for it (I don't really like playing with children, cheaters and trolls though). I also like to play Zombies and I like what they've done with that.
I'll paste a bunch of observations I've been emailing to friends:
First off, this is NOT available on Steam. You have to buy it from Blizzard and use their BattleNet service. On the flip side BattleNet is pretty damn smooth and seamless - a nice clone of Steam.
I've gotta say I love the idea of a zombie map on the Titanic, and it looks awesome. Actually ALL the Zombie maps (there's 4 if you buy the digital deluxe version) are awesome and HUGE. Quick tour of the Titanic map (Voyage of Despair) here:
https://youtu.be/13CdO-b6dMc
There's now difficulty modes in the standard zombies game, and there's a completely customizable gameplay "mutators" mode that can let you tweak everything. For instance you can give yourself extra money and health at the start of the game.
This video author says "The implementation of custom mutations is huge for re-playablity. It gives you the freedom to make the game as easy or as hard as you want."
Overview here:
https://www.youtube.com/watch?v=zG6qXneBXDA
Detailed mutation rules listed here:
https://youtu.be/RB4dc3-ErdQ
You can do things like adjust your starting money, starting health, health regen speed, have kills give you health, disable the dog and other special rounds, start the game with the power on, have ALL the mystery boxes on all the time, have the Pack-A-Punch on at the beginning, adjust zombie min & max speed, disable zombie types you don't like. Oh and my fav: KEEP YOUR WEAPONS AFTER DEATH.
Also (and this is new) you can play Zombies with Bots. So playing solo isn't so bad anymore, and the bots play very well.
Regular multiplayer is good. Nice maps. Setup for a private match with bots is pretty much the same as previous games. Bots play very well. The new large maps work better than the 3 remakes of older (and smaller) maps. A couple of new multiplayer modes that are good like Control and Heist.
There are reports on gaming news sites that the tick rate on multiplayer servers is lower than the beta (20 Hz compared to 60 Hz) but I haven't noticed any problems. Online multiplayer seems pretty smooth and no hit box issues.
I'm getting 85+ FPS right out of the box at 3440x1440 on a GTX1080 with the default graphics settings. Since my monitor has a 100 Hz refresh I'm good with that and it feels smooth.
Black Out, which is their version of Battle Royale, is actually quite good. This mode is not really my thing, but I find it much easier to jump into in this game than Fortnite. There's less rummaging around. If you land near any buildings you'll find plenty of weapons and med packs and can get right into the action.