Have a search through, I've commented on the branch a few times. I'm not a lawyer and I can't really comment on the legal career side of things, but there seem to me to be two distinct sides of the branch, the courts martial side of things, defending/prosecuting within the military system and then the LOAC advisor in HQ, which is a rapidly growing area (or has grown rapidly in recent years, may not still be growing).
Because it is such a small and specialised branch, it is much more open to requests for information, so if you can find anyone called SO2 (Legal) or SO1 (Legal) say at High Wycombe, contact them and they are likely to tell you a lot more.