Reading this thread has re-confirmed three points for me:
1) most a/c have two com boxes. Use them. LARS as primary, a/g listening.
2) for the sake of a few minutes, route to the south of stapleford (or if you're feeling lucky a zone crossing of stansted)
3) what a complete waste of time a basic (any non radar derived) service is - in the busy areas of the south east. Ie I sometimes feel you get the same utility from talking to an a/g as you do from a lars BS !!