The vampire class is something that should be discussed with the group and the DM before bringing it to the table. I wouldn't advise just showing up at the table with a vampire and expecting everyone to be okay with it. Sure you have some groups that only focus on the mechanics and really don't care, but you also have groups that care about the role play and want characters coming in to actually fit the campaign.
I think the biggest problem with the class is the requirement to feed from your companions. I don't understand why the rules weren't written a little different. I could see the vampire knocking an enemy unconscious and feeding from the victim after the fight is over, or Dominating say a towns person, taking just enough and then letting them go with no memory of it.
In my opinion the designers created a controversial class.
I'd answer this two ways:
1) There's no REQUIREMENT that the character ever feed off his allies. His low healing surge number means there are probably going to be SOME situations where that is a good option. OTOH remember, he does have regen 5 while bloodied, so most of the time the character can lay back in that kind of situation if he really has to and avoid ever sucking on his allies at all. Taking toughness (and durable might help as well) doesn't TOTALLY mitigate the problem, but it goes a long ways. I mean there are classes that have 6 surges and no way at all to gain more, and they're perfectly viable. A Vampire with 4 surges, surges that work better than normal in some instances, the ability to get more surges, and regen 5 while bloodied is actually probably better off than your average wizard even BEFORE you talk about sucking on your allies. It really isn't that dependent on this one feature.
2) It is meant to be controversial, yes. As I've said in a lot of other places, and probably up further in this thread, a vampire that fails to embody the concept of a vampire merely because it would be inconvenient or is tricky to play or balance with other classes is fail. It isn't a vampire, so why even bother to make it? There's no point in having a Smurphpire class. A vampire needs to be a VAMPIRE to justify its existence as a game element. In any case you can take the Dhampyr bloodline feat, the Vryloka race, etc. and be a milder form of vampire if you want, which is fine. The Vampire class is "I'm Dracula baby".
As to how much hand wringing has to go into bringing it into a game, that will kind of depend on the group. Personally I'd feel slighted if the players all showed up at the table for a new campaign and singled out my choice of character as being an issue (regardless of what that choice was). OTOH there are dick players that will make a vampire simply to be troublesome as well. Reasonable players will accommodate each other's wishes. It shouldn't be a big deal most of the time, and if the DM has restrictions on what he wants to see played in his game, well those really should be up front.