I really like Organic Deli Cafe. Yes, their service can be a little idiosyncratic, and sometimes they run out of butter and substitute cream cheese. But there is nowhere else in Oxford as sympathetic to people with food allergies. Here you are not made to feel weird for wanting gluten-free bread (homemade, delicious) or non-dairy milk in your coffee. Here you actually get a choice rather than having to take The Gluten-free Option.
On our last outing we had toasted gf sandwich with hummus, falafel and roast veg, and the veggie breakfast. The latter was unusual and smelt fantastic, coming with a lentil rissole, jacket potato and other quirky foodstuffs. There was no substitution of fake meat for meat - this was a well-thought out combo. The toasted sandwich was delicious and very filling. It falls apart a bit but that's what gf bread that isn't full of additives tends to do. As usual I forgot about the extensive tea menu till after I'd ordered coffee, but the coffee was really good.
If you have a Oxford Bus Key you get 15% off your bill. That means the prices compare favourably with all the other local cafes, for better quality food.
The quirks of the place such as running out of ingredients and substituting other things are not something I mind - they stem from buying small amounts of good ingredients and from running a tiny, very busy establishment with not many staff. This cafe has its heart in the right place. I'd take that over a slick megacorp any day.