...this is the way people talk. How you could have a story set where and when this story is set, among these characters and not have profanity is something I don't see how it could work. Keep in mind, not all the characters do curse very much, if at all. But some do, and that accurately reflects life.Likewise, the story is about--among other things--sex. That is a perfectly valid thing for stories to be about.
There are a lot of differences, though. Bill is far more diplomatic than Barnabas, and seems more comfortable with his vampire status. He isn't nearly as aristocratic, nor seemingly as vain. Not a ring or over-elaborate cane in sight! If anything his wardrobe is very ordinary. Plus he doesn't seem as obsessed with the past, the way Barnabas was forever dwelling on what had been (often at the expense of what was or could be).