I am currently in the closing process for an AKV contract I purchased through Fidelity. My opinion is, I got a much lower price through Fidelity and am very pleased, however, I do think it takes more time and you do have to call them to get updates. I would also add that they do seem to have more contracts but they are slow to update and many of those contracts listed are not available. Bottom line is, if you are looking for the best deal, I would definitely recommend Fidelity, but if you are more concerned with time then I would say TSS. From my limited experience, with Fidelity you seem to have more ability to negoiate and with TSS they seemed to encourage you to offer asking price. Good luck