Slack said...
Mate forget the impact vest and get yourself a crocheted blanket and stay home.
ie. HTFU!
Didn't you get winged recently petal?

Bet the blanky felt nice then

Ian - I was extremely grateful to be wearing a vest, at least twice on my last sesh.

I was surprised not to have actually busted a rib even with a vest on after one particularly monster stack (this sesh also featured my biggest kitemare so far but that's another story).
Ultimately if it keeps you on the water or gives you more confidence to boost (or whatever) a bit higher/faster/harder then go the vest I reckon.
Leave the HTFU brigade to sit on the beach nursing flogged ribs.

EDIT-
Kitemare details as requested:
www.seabreeze.com.au/forums/topic.asp?TOPIC_ID=44499