That new "old style cheesecake" joint at 94 Third Avenue between 12th and 13th Street is up and running. Any preliminary reports? At least the menu seems authentic: You can indeed get steak with Cheez Whiz (or American or Provolone) "wit'" or "wit'out" onions for $5-6. Lots of other add-ons, including double cheese, mushrooms, and sweet or hot peppers at 50 cents. Waffle fries $2. Anybody?