Kuy,
On Madison, we sail with auto ratchets on the stern blocks; this one way to implement Mark Allen's suggestion. These are from Harken. We set them to the "max spring setting" with the hex key. This setting requires the most wind load on the sheet before the auto ratchet will kick on (usually about 6-7kts). From 0-18 kts, we just run off the rear auto-ratchets with the ratchet mechanism engaging based upon the sheet load. Over 18 knots, we put the turning block ratchets on as well so the sheet has an in-line double ratchet. This provides a light sheet with finger tip control in 18kts and we have had it out in 25kts no problems (I believe this is the same configuration that the Melges 24s have gone to as well).
Occasionally, in a jibe or douse the released sheet will get snagged and this will load the sheet and turn the stern auto-ratchet on which is annoying, but once it happens a couple times you know that is happening and quick flick of the sheet up will get it running again. This is the only downside I have experienced with this configuration. In up and down conditions that are 5-9kts it is nice because the ratchet will turn on and off automatically without having to move around the boat.
Jay