Keystone Korner is a popular sandwich shop with a cozy and casual atmosphere. The staff is friendly and welcoming, making it a great spot for solo dining, family meals, or group gatherings. The menu features a variety of sandwiches, including Cubans, Philly cheesesteaks, and Italian subs, all made with freshly baked bread and high-quality ingredients. While the food is generally good, some customers have reported issues with inconsistent quality, with some sandwiches being overpriced for the portion size. The shop also offers outdoor seating, making it a great option for those looking for a quick and casual meal. However, some customers have reported that the menu has changed significantly, with some favorite items being removed, which has affected their overall experience.