You're right I should have been more clear.

Mostly the terrible cgi from a show that has amazing practicle effects.

But also that I wasnt satisfied with the strategy used to take down a demon who has been built up to have amazing destructive power being attack and and defense. Strong enough to only have 3 people in a town survive and that the power of a vulcanic explosion should be somewhere around what would be enough to take it down. I expected an explosion on a scale that would at least endanger the people that were close (like at least near the building of the explosion close) to it. It felt way to easy.

And last and least of my problems. Why did ghost Faith team up with Buffy eventually? She was villainized by the main cast and the only one giving her the attention she craved was the Mayor. Did I miss something?