Zombie holds a slight advantage, as it downscales its value and Tank upscales its own, being this a difference of 3.71x. In terms of skill, they're pretty much the same, since they're both mindless. Although they do have a few very minor traits that stand out, such as Zombies being capable of aim-dodging and the Tank using its surroundings to its advantage by throwing crap.
LS difference looks significant, but that's mainly because, as I mentioned, I haven't updated the Zombie's values yet; while the Tank would still have the advantage, it wouldn't be by much, but anyways I'd rather ignore information that hasn't been properly listed yet.
Infinite stamina is pretty lame for the Tank (as well for Superhuman to all L4D2 characters fr), I'd even say it shouldn't be there, and the Zombie far surpasses it in this one.
Although the Tank can pin the Zombie down by grabbing him, the Zombie has higher reaction speed, which could allow him to counter this, especially when combined with his AP advantage.
For now I'm voting Incon, leaning like 51% in favor of Zombie maybe.
