You may hit for paltry amounts, but I'm willing to bet that you don't factor in your ghoul's damage and the use of a stun.
I did, it's just that back then, Ghoul Stun helped me **** all. Situations I'd get in were those along the lines of;
A priest casts up a heal, I Mind Freeze him. He casts up another heal, I run out of melee range and DG him. He tries yet another one, I use Strangulate. Another heal, I Mind Freeze it. Another heal, I use Ghoul stun. By this point the priest is on 60% hp and I've used all possible interrupts I've got. He casts up a heal and goes back to full. GG.
Ghoul Stun didn't really add anything besides the ocassional interrupt while I was CC'd myself. If you can run up to a priest, unload on him with your CDs and take him to 20%, you see more result. The Ghoul's damage wasn't even noticeable.
It's all pretty much worthless anyway at this point, since 4.0 is right around the corner.
I still think that unholy is far, FAR superior to blood and frost in PvP.
It was back then, by now it probably properly is. It got a lot of buffs and really the only thing Blood has left right now is Vamp Blood (+Death Pact) and Rune Tap.