I always use Trailfinders to book my journeys when flying with BA. I always request certain seats, and although a BAEC Member, only lowly Bronze I’m afraid, I have always been given the seat requested. Even though I book some months in advance I’ve never been allocated a different seat from the one requested. There is of course the usual proviso from BA about seats possibly being moved to another seat, this has never happened to me in the last 11 years. We’ll wait and see what happens now when I check in for my November flight!