It's all about the fine-tuned chemistry between the two lead characters. That's what made it work for me.
If one tries to compare this to other Kevin Smith films, it's a close third, mostly because (1) I will always have a special spot for "Clerks" that started it all, and (2) I'm biased towards "Dogma".
And, oh yeah, my wife and I saw Bruce Campbell last night during a premiere of "My Name is Bruce" at the Kendall.
