No Au Bon Pain in CA?
I find Panera to be less expensive and better quality, but that's just my opinion. I find Au Bon Pain to be fairly pricey for what you're getting. I think there's also healthier options at Panera and I like the 'pick 2' options (half a sandwich and soup or a salad and soup). I'd even choose Cosi over ABP. I don't think you're missing much! :)
I think Au Bon Pain offers more options, they have about 6 to 8 different soups and such daily and they are usually more interesting the ones at Panera. They also have lots of ready made sandwiches, salads and snacks (like a couple of cubes of cheese and a few slices of fruit) that are in containers and can be picked up quickly. Those items are the ones that can really add up when you realize what you are paying for, but I like the convenience of those when traveling.
You can also get the made to order sandwiches and salads but there are often long lines for that.