The canvas on a properly made one does not bag like the power sailing one. It stays up tall and tight to the main and conforms smoothly to the sail shape so it does not have much impact on performance. The canvas is actually sewn along the foot of the sail unlike the powersailing one which wraps under the boom. The bag is what captures the sail, the lazy jacks are just a guide. The lazy jacks are independant from the sail, no penetrations, no grommets like a dutchman system.
It's not like these are a new thing. Go cruise in the Virgin Islands and you will find almost every boat there is equipped with one. Check out the Sunsail or the Moorings fleet pictures in the magazines. Look at almost every sailing cat ever made. They all use this type of system.
http://www.doylesails.com/sails-cruisin ... ckpack.htm
There is no way I'd tolerate removing my boom or sail when not sailing. There is no room for it below to begin with, and it's far to much time and effort. My family of 5 lives in the boat for extended periods of time. A 10' hunk of aluminum has no place down below. Put the slides in once, raise or lower the sail when needed from the cockpit, zip the cover closed when not using it. Taking it off is nothing but a pain. A totally unacceptable choice on my boat.
Obviously UV is not an issue at night, but if you are just dropping the sail into the sail caddy and leaving it there it will also spend quite a few daylight hours exposed. Why not use a cover, normal or top opening. It looks proper and protects the sail to boot. We don't need our macs to get a reputation as the sloppy looking boats with lazy captians out there.
