The new ZS is better. It's not an opinion, it's a fact. And unless you've played it for more than five rounds, any counter-argument you may have is invalid.
The biggest, and probably the most wonderful part of the revamp was the buying and point system. It adds a complexity to the gamemode that the old one never could have; you could spent all of your points on weapons and ammo early on, and have less in the later bit, or spend all of it on being a support role, then having more. There evolved roles. Support medic, heavy medic, early assault, caders, crate support, etc. You could be whatever role you enjoy the most and, if you feel there's a role missing, you can fill it.
UI. 100% better, there is no argument.
Gameplay: The new ZS encourages being helpful. Unlike in the old ZS where a cader just slammed down on nails all day and had shit weapons, you could be a cader, fixing nails and gain considerable points over time and still get decent to good weapons.
One of the best features that was put in was the ability to pack up your crap. If you put down ammo crates, arsenal crates, aegis boards, or turrets, you can pack them up and move them on your free will. And if someone decides to be a complete shit and put down a tool in a bad place, you and four other people can all unpack someone else's stuff. You can also slow-clip through nailed and placed props. No more being trapped like old ZS.
Bug Fixes: No more five foot drop deaths, only hp loss, 99% of prop collision deaths are now fixed.
And before someone starts screaming how great timed ammo drops are, it's still there. And you still do the same thing as you did in old ZS; you draw out the weapon you want but now you interact with a player placed ammo crate which client-side refills after a bit of time