Imo due to draw backs of city's attacking u when ur full vampire you should get alot more than you get. Vampires should be more powerful than the werewolfs because really there is no reason to want to be a vampire.

I hope someone puts out a mod for this.

No need to rest on hope: this is inevitable. We should see Vampirism mods shortly after the CK is released because this is a subject with many eager modders.

There are at least two developing threads going on vampires also. You should look them up and share your thoughts (search feature is in the upper right corner of the forums).