CB1 seems to be more vegan-friendly every time I visit. It's very friendly in attitude too. With a real sense of being part of the Mill Road community, it's a great place to relax, see friends or study that's quite unique in Cambridge. They're often open late.
The food is great value. Many of the ingredients are organic (soil association certified). The hot items/specials change fairly often, which is nice. Lately they have lots of vegan snacks/treats available. I like their coffee too (I'm very picky!).
Although overall it's cosy with comfy furniture, the downstairs seating area less so. It is a bit stark down there, and can be cold & dark in winter. I wish they could get more natural light in somehow. If they did that, and had an outdoor area for summer, CB1 would be perfect.
Cons: Downstairs seating area is less nice, Dimly lit at times