Is there anything Sunshine didn't improve? The effects of high explosives on her Buffyesque vampires was I think unspecified, but targetting would be clearly a problem. They're fast, and have the enthrall on eye-contact thing going for them. As for lair-searching[1], the vamps can't kill in daytime, but their other mojo might work, and daytime guards are mentioned in an ominous fashion, though for all we know those were just hired humans with guns[2]. Plus it's not clear there'd be any mortal entrance to a mastervamp lair. So the human gov't knows about vamps and has our tech and some magic, but it's still at best an even fight.

[1] I forgot to mention in my other entry: there were various occasions on Buffy where I thought "look, you know where the lair is. Go knock holes in the roof during daylight. Or burn it down."

[2] I still love the image of master vampires hiding in their basements and lurking on the Internet. It's up there with S1 Buffy: "Whoosh, they're gone." "Vampires can fly?" "They can drive."