I read the Nagash series without knowing anything of the other lore (beyond the army books I have). Reading the stuff in Nights Dark Masters was interesting. I had always thought of Vlad as one of Vash's first born because I assumed Vashanesh would be a little more... powerful especially considering he was the beginning of a blood line. I don't think the books and NDM are so terribly different if you exclude the whole "little" ring thing. I look at it as though the Nagash series was written from the perspective of the people at the time and we don't know who "wrote" the information in NDM and it happened so long ago, there's bound to be more than one account that has truth to it. I thought the Nagash books were good and I'm looking forward to the Neferata trilogy.
Oh and cabbage = evil
"I've heard Vampires travel around so easily because those filthy gypsies, the Strigany, shelter them in their caravans. I wouldn't put it past 'em. They're horses thieves and adulterers, and they all reek of cabbage. It's a short walk from there to harbouring the Undead if you ask me."
-Azmus Pacher, Horse Trader
Oh and cabbage = evil
"I've heard Vampires travel around so easily because those filthy gypsies, the Strigany, shelter them in their caravans. I wouldn't put it past 'em. They're horses thieves and adulterers, and they all reek of cabbage. It's a short walk from there to harbouring the Undead if you ask me."
-Azmus Pacher, Horse Trader