While TS4 is not the best version of the sims, the Vampire pack is pretty awesome.
They're the best version of vampires the franchise has ever had.
TS5 is something I'm hoping for, but not too soon, because they need to do one thing in particular with it, that they failed to do with TS4, and that is not rush it out before it's ready. The base game needs to run smoothly, and contain the things it should contain, such as at least open neighbourhoods, toddlers, pools with diving boards, shower woohoo, snuggling in and on a bed.