I'm not talking about the zombies of We're Alive, my question is specifically about zombies in movies.

Do you think that slow zombies (such as those in old-style George Romero films) or fast zombies (such as those in more modern zombie films like the Dawn of the Dead remake, Resident Evil etc) are scarier?

I have been considering this since I read Simon Pegg's piece on why zombies ought to be slow, which was in reaction to a British TV series that was made a few years ago with fast zombies.

This is the most relevant section of his article:
I know it is absurd to debate the rules of a reality that does not exist, but this genuinely irks me. You cannot kill a vampire with an MDF stake; werewolves can't fly; zombies do not run. It's a misconception, a bastardisation that diminishes a classic movie monster. The best phantasmagoria uses reality to render the inconceivable conceivable. The speedy zombie seems implausible to me, even within the fantastic realm it inhabits. A biological agent, I'll buy. Some sort of super-virus? Sure, why not. But death? Death is a disability, not a superpower. It's hard to run with a cold, let alone the most debilitating malady of them all.

More significantly, the fast zombie is bereft of poetic subtlety. As monsters from the id, zombies win out over vampires and werewolves when it comes to the title of Most Potent Metaphorical Monster. Where their pointy-toothed cousins are all about sex and bestial savagery, the zombie trumps all by personifying our deepest fear: death. Zombies are our destiny writ large. Slow and steady in their approach, weak, clumsy, often absurd, the zombie relentlessly closes in, unstoppable, intractable.

However (and herein lies the sublime artfulness of the slow zombie), their ineptitude actually makes them avoidable, at least for a while. If you're careful, if you keep your wits about you, you can stave them off, even outstrip them - much as we strive to outstrip death. Drink less, cut out red meat, exercise, practice safe sex; these are our shotguns, our cricket bats, our farmhouses, our shopping malls. However, none of these things fully insulates us from the creeping dread that something so witless, so elemental may yet catch us unawares - the drunk driver, the cancer sleeping in the double helix, the legless ghoul dragging itself through the darkness towards our ankles.

Another thing: speed simplifies the zombie, clarifying the threat and reducing any response to an emotional reflex. It's the difference between someone shouting "Boo!" and hearing the sound of the floorboards creaking in an upstairs room: a quick thrill at the expense of a more profound sense of dread. The absence of rage or aggression in slow zombies makes them oddly sympathetic, a detail that enabled Romero to project depth on to their blankness, to create tragic anti-heroes; his were figures to be pitied, empathised with, even rooted for. The moment they appear angry or petulant, the second they emit furious velociraptor screeches (as opposed to the correct mournful moans of longing), they cease to possess any ambiguity. They are simply mean.