Except it's still the same railgun twitch gameplay that Q3A had. There's no bullet travel like Battlefield has. The physics feel like a cvar tweak instead of a totally different mechanic (I'll get them a slight benefit of doubt they changed/modded this since there's no air physics or rocketjumps, obviously).
Treyarch poster here two years ago: "We changed the physics and lighting systems! It's a completely new engine!"
Me: "Uh, dude, you may have taken some things out and added a few new things. But under the hood it's still the Q3A engine. No matter how much you protest it isn't."
And until they stop having hit scan no-recoil "modern" guns, it's always going to be regarded as the Q3A engine to me because the guns feel like the Q3A railgun. Even the sniper rifle.
In fact, Carmack remarked on this with a "you know your engine is good if it's still being used 10 years later" remark. So...