Sorry to hear about your first experience as a Diamond. Generally, at check in you receive an amenity card where you get to select the type of beverage & snack you want. I've stayed at the Baltimore Hyatt (the one at the Harbor?), and it isnt that great. The last time I was there the Regency floor was full so they gave me a nice corner room overlooking the Harbor but with access to the RC. The RC is very small with a couple of chairs & tables and a TV. The evening snacks were kind of sparce, but the breakfast was good. All in all, the Hyatt Baltimore is not one of their best.
PS- I've never stayed overnight at the Hyatt New Brunswick--but I wouldn't count on anything great there. There are a number of very good restaurants within a 3 block area of the hotel though!