Been here about twelve times, only had an order mix-up once, which they corrected without making any issue.
Here's the process: Walk-in (research the menu online at home before you go) find the proper paper envelope on one of the carousels which has the category and kind of sandwich you want. Start at the top marking how you want it fixed, one sandwich per envelope.
After marking, hand it in to the person at the register then wait for your name to get called. Be warned, it is hard to hear your name called due to the noise in the restaurant and the way the counters are built. I put a big red mark on the back of the envelope so I can see where it is in the process and when it comes off the clothes line, ready for me to pick-up.
I've had both the Italian Grinder and Muffelleta both of which are decent. I've eaten them at home the next day after all night in the refrigerator and found them still decent.
Parking can be a problem here. The parking lot is cramped and tiny. This is one of those lots that's laid out on a computer, so traffic only flows well in theory, be patient and be prepared to park further away and walk.
I've found the staff is always professional and work focused. The inside always clean. My only complaints are how hard it is to hear your name called, and the parking lot being designed around the Smart Car.
Just an FYI: sliced tomatoes on a sub leads to ingredients sliding and the sub falling apart. I love sliced toms but find eating is a much nicer experience without the tomatoes.
If you go here during lunch or dinner time be prepared to wait 10-15 minutes for your food to be prepared.
You might want to check the nutrition info on their web site before frequenting this place, the numbers are not great which is sort of no surprise when compared to other sub shops.