Alright, more thoughts. (Warning: Rant)
One change I utterly detest is that the assault rifle and the minigun have a much higher fire rate. The assault rifle's change removes it's older role as a bullet conserving and easily controllable weapon, and makes it expend it's smallish magazine much faster, meaning you have to stop dishing out pain in order to reload much more. The minigun has it's already high fire rate seemingly doubled, making it expend ammunition stupidly quickly and changing it from a weapon that could be depended on for many situations, from mowing down large groups of zombies to eliminating multiple tougher targets, into a weapon that tears apart a Baron in two seconds flat and is completely overkill and a waste of ammunition for most situations it used to excel at. A whole extra bunch of effects, like gunfire smoke and spent belt segments being ejected, are also added to the weapon, making it bog down the framerate much more than it used to.
I'm also not a fan of the pump shotgun having a higher rate of fire when in iron sights mode, instead of having a tighter spread. It kind of goes against the point of using iron sights, which is to shoot with greater precision. One might say it isn't realistic for the spread to tighten when in iron sights mode, but I prefer practicality over realism.
And Mark brought the annoying zombie scream sounds back. Why? The v20b sounds worked perfectly and weren't grating on the ears.
Like Pyrolex said, the new punch sprites look stupid. They look like Doomguy is raising his arms next to his face and then punching. I also don't like the new punch system, which is like PB's melee system, but shitty. The old left-click-weak-executing-punch-right-click-strong-gibbing-punch system was much more predictable, practical, and simpler to use. Currently, to execute a Pinky, you have to mash the buttons and hope it doesn't gib it, while earlier it was left punch+right punch=done.
The Chainsaw goes back to being swung around like a madman. I liked the swinging better when it was an option, and you could just use the chainsaw like in vanilla.
Still, there are things I love: the vehicles, the new weapons (in particular the SMG and the Machine Gun), the new sprite work, the grab system, and the raise-after-firing thing being removed from the Plasma Rifle.