Overall: I love sandwiches and this is my go-to, especially for a good, solid classic-style sub. I keep coming back to their Italian and Mike's way is the only way!
Food: As noted, while they have a couple of fun subs like the Big Kahuna Cheese Steak, I feel that they hold it down when it comes to a more "traditional" approach with their subs: good bread, quality meat and simple ingredients. That's not to say that traditional is bad. Other sandwich spots have their angle. Jersey Mike's just puts a product that stands more on keeping to simple ingredients of quality than venturing into the hit-or-miss territory of inventive subs.
Staff: I have been here plenty of times (many of times I even forget to check in....I get sub-sandwich-tunnel-vision) and I have never had a bad experience with the staff. They are professional but they are also fun and talkative; they do not go into that mechanical sandwich-making auto pilot mode you see at other spots. Also, while it looks like chaos at times, they are very good at assembling multiple subs at once (when I go...it's usually for picking up an office order so it's usually 4-8 subs).
Facilities: I usually take my food to-go but their facilities are always clean. Additionally, all of the location I have been to have had plenty of seating.