I voted 9; it's a good level since you've already gotten your second stat bonus, just got a new feat, your weaker saves go up by one.. You're officially in the "Big League" now: Full casters get their 5th level spells which have fun things like teleport, raise dead, wall of thorns, and cloudkill.
You're a big potato but not so powerful that you can ignore mooks. You can influence a town but still can't boss everyone around.