Andrew Barnett's long-awaited return to coffee roasting is open and worth checking out. Linea Caffe is on 18th Street behind Duc Loi, the Vietnamese grocery store at 18th and Mission. Barnett has long-standing relationships with several Brazilian growers and features their coffees in his new espresso blend. It's a smooth and sweet espresso that never heard of bitter.
Also available at Linea are Belgian style waffles from Anthony Myint of Mission Chinese. The waffles are magically light and crispy. I got mine with yogurt and strawberries, and it was fantastic.
Linea is a hole-in-the-wall spot with no seating at present. (Outdoor seating is on the way.) But it's worth checking out for both the coffee and the waffles. (Not to mention the salads.)