I've been to the Mill a couple of times since it opened. The Bread is fanstastic - if somewhat expensive. I'm particularly fond of the "Mountain Loaf" which is a whole grain rye with linseeds and sunflower seeds (and probably some other seeds) done in a classic German style. I would say it unseats previous bay area champion Esther's for german style whole grain bread. The whole wheat sourdough was very sour but with an excellent chewy crumb. I hadn't had Josey's bread before going to the Mill but have to say it's clearly in the running for best bread in the area (of course, in the Bay Area we are luck to have _many_ places on that list).
The coffee (Four Barrel - my favorite locally) is excellent. In addition to selling bread they have a small pastry selection and a number of 'toast with toppings' options.
The bread is excellent which of course leads to great toast. That said, I don't think I'll ever buy toast there. At $3.50-$3.75 per slice it runs more then a fancy pastry in many places and just two slices buys you a whole loaf of bread. Seriously. The prices for toast are completely ridiculous. $1.50 or even $2 I could stomach.
Unless you're eating toast as part of an ironic performance art piece, skip the toast and just buy a loaf of bread.
Some of the breads that you can have toasted they do not sell by the loaf. I wanted the sour dough loaf but was told they only sell the boule even though they use the sourdough loaf for slices sold in store. (The square loaf size is a lot more convenient for people making lots of sandwiches for children. My request got blank stares from the people behind the counter and a bit of a surly response when i tried to explain why I wanted a loaf.) They do not have a bread slicing machine. The service was otherwise friendly.