The Mezzanine

But after the first couple of seasons they seem pretty consistent overall that Buffy is stronger than most vampires. She dispenses with them easily. And at some point or another I think both Angel and Spike mention that she's stronger. I think generally they avoided too many visual cues about it because it tended to look silly (such as the time they tried to make it look like teeny-tiny SMG was carrying Michelle Trachtenberg and the proportions just looked... unweildy. Troll hammer wasn't as visually silly-looking. But I never understood why a troll hammer would necesarrily be 'easier' for a Slayer. the mythology doesn't overlap and both Slayers and Vampires are demon-powered so I'm not sure where there would be an inherent preference (unlike Slayer Scythe which was a Slayer-specific weapon).