Having any type or size of ratchet on the Jib sheet, in my opinion, is absolutely essential for any size, shape or strength of crew. My main reason for having ratchets on the jib sheet is so i can ease the jib a bees wotsit in a lull, or when we need to grunt up the jib for a bit of choppy water… (they are also good for windy two sail reaches when i can’t see anything) Without the ratchet, its hard to control the amount you ease, inevitably you let too much out then re trim. There are others pros as well for ratchets, can’t see many cons apart from the extra ££. For what its worth, we use 40mm switchable ratchet blocks from harken, and we use a 6mm calibrated/marked sheet. Even with 6mm sheets, it does help light wind tacks if you can turn the ratchets off.
The Flying Fifteen Blog 