I enjoyed Watchmen and 300 for what they were. Never saw Dawn of the Dead, but I agree that Snyder is a bit overrated. He obviously mixes just enough nerdiness to sell to the hardcore with the right amount of ass-kissing to get the big budgets he needs from the studios.
I think with 300 he just went 100% for the visual copy, like "how close can I get this frame for frame." That film caught the zeitgeist and took off so from then on he's been chasing that. Watchmen was a total reach for that kind of "BIGGEST THING GOING ON RIGHT NOW" with the cast appearing on morning talk shows and shit left and right. But for all the "as close as possible to the source material" he still had to mess with the ending to make it palatable to the massive audience he was chasing.
Anyway, I'll still see it. :-/