Thanks for posting the above Malcolm; I'd also be interested to see what any other members who've dived with these think.
In fact, if anyone can give any useful reflections (sorry, lousy pun!) on the two questions below, it'd help:
1. Does the fact that the light is central and close to the eyes cause a lot of scatter?
2. Does the battery, which seems to stick up slightly, become a problem in difficult terrain?