How have vampires turned out in Dawnguard and where do they live?

Off the coast in the North West.

Not generic

How does that stop them from being generic? are the volkihar as described in lore or are they the same as generic vampires?

Instead of being generic vampires the Valkihar are pure-blooded Vampire Lords. Like Harkon can transform and use the special VL abilities.

They are as generic as vampires could be, I don't can think of a cliche that isn't in: bats, coffins, blood drinking like wine, mostly black and red clothes, a generic castle with gargoyles and yes they want to turn out the sun.

No foreign Ice Vampires, nothing fascinating.

Creativity und uniqueness don't seem to be a important thing to Betheseda.

Hehehehh, that's a lie.

They don't come crawling out of ice if that's what you're talking about. That's more than likely superstitious exaggeration.

They dont follow the book "Immortal blood" but it follows the lore,

So, it doesn't follow THE lore but it follows SOME lore?

Vampires look boring