We will be celebrating our first trip to Chicago in April. Need great food recommendations. We have reservations at Arun's and we're thinking about Rosebud. Both are close to the Park Hyatt, where we will be staying. Any Chicago specialties we should know about (we know about the hotdogs)? Chicago has a reputation as a great food town and we're willing to splurge. Also, feedback on Rosebud would be appreciated.