I use Grimgor in every game with my Orc army (its themed around Grimgor's Ard Boyz, so hardly any goblins, just lots of orcs), have done since the last army book. I really don't see why people think he got nerfed. A 20 point increase and the loss of 2 attacks, yes; but his unit got a point cheaper per model (so as long as you take 21+, he's actually cheaper than before) and +1Ws. I much prefer the new Grimgor to the old one (oh, and he's now S8 in the first round as well).
I quite like Vlad, because he seems like a decent all-rounder. He's a Lv3 Wizard, he has a very nice weapon (really wish my regular lord could take that, instead of crappy Scabscrath ), and he actually has a ward save - so unlike the other vampires he's not running round with just heavy armour, and praying that nothing has killing blow). Coming back to life on a 2+ is very nice, since it counteracts a lot of things (silly ID spells, kiling blow, combat-resolution etc.). The only thing I find sad is that he only gets ASF when Isabella is not only present, but in the same unit (and loses it if she dies). If he started with that, and got something else when she was around, he'd easily be my pick for best character. As it stands, he feels a little overcosted (especially since I can't help but look at Isabella as a 170pt make-Vlad-good-in-CC tax). Still, he's probably my favourite out of the VC book.
In terms of the other books, I'm not really sure. The only other 8th edition book in my group is Ogre Kingdoms, and the player never uses the special characters, so I can't really comment on them.
I tried a Skragg list a few times at 2000 points, it's actually not too bad, but only having one unit of ogre's the way I did, so as to maximise the Gorgers, was extremely risky and could easily be defeated.
But that was just my way of doing it, although on the other hand; why would you take skragg and not take loads of gorgers?
A boy played in the sandbox with no one to mind him,
When quietly a mixing truck pulled up behind him.
He peeped not a peep, cried out nary a cry —
Just his sandals stuck out when the concrete was dry.
Vlad and Isabella Von Carstein are two of my favorite characters in the Fantasy world. Their doomed romance is probably one of the best pieces of fluff in the game.
If I played Vampire Counts I'd always take them. As it is I'll have to swallow my distrust of Finecast and buy them to paint.
In Empire I'd have to go with Marius Leitdorf. Cheap enough to play in 1000 points he brings 4 WS6 Runefang attacks along with the normal General rules.
"Reason is a thing of God, inasmuch as there is nothing which God the Maker of all has not provided, disposed, ordained by reason - nothing which He has not willed should be handled and understood by reason" Quintus Tertullian