I have had dutchman on 3 boats including the one I own now. I have had the
Harken lazy jacks on one boat and took it off and did without rather than mess with them. I do like the dutchman, but replaced the monofilament with 1/16" vinyl SS wire. It does not stretch and make the system work a lot smoother. I can literally drop the sail and tie it off to the boom. Very little effort compared to fighting it when loose. My vote is Dutchman, though the parts are ridiculously expensive.
DD