One of the issues with Pret - and most of the other pre-made sandwich places, is that they are extremely mean with the filling. What filling there is is piled in the middle and sliced through, so that it looks like there's nearly 1cm of filling, whereas there's next to none anywhere around the edges.

I know Leon don't do sandwiches, but I do find their lunch food to be significantly better than that of Pret or EAT.