I had my reply back from the BBCwritersroom today with the reader's notes. Rather unsurprisingly; the script needs more work, but the notes that the reader has added are invaluable and offers areas in which improvements can be made. On the positive side they did compare it with 'Spooks' and the US series' Sleeper Cell and NCIS.
It may take a while to get a reply to work sent into the BBCwritersroom but, assuming you get a full read, the notes they provide offer an insight which may not have occured to you at the time of writing and can guide you forwards with improving. And it's free.
I think I'm going to let the notes sink in and re-work this in time for a Red Planet submission - assuming that they're running their prize this year.