Anyone have first hand experience with the Dutchman mainsail flaking system, 10,000 sets sold and it looks easy to replicate, but is it any good?

manualzz.com/doc/1194464/martinus-van-breems

No first hand experience but it looks way too complicated than it should be, also tying up your boom topping lift with the lazy jack system for no good reason.

I installed a lazy jack system on a 24fter with single spreader rig with spectra lashings around the spreader roots holding a pulley each side then going to a system like this - when it worked so well and I had the mast out to refurbish it and re-rig it I tapped in metal thread hex screws holding pulleys to the mast (with tefgel) just under the spreaders for the system but made holes in the mast for no good reason.

www.harken.com.au/en/shop/lazy-jacks/small-lazy-jack-kit/

See here other systems

www.modernsailing.com/article/sailing-lazy-jacks-and-stack-packs

Those 10,000 systems sold imho have been well overtaken by similar systems to the above. If you have in mind a lazy jack boom bag like the below from your local sailmaker that could interest

www.rollytaskersailsaustralia.com.au/online-store/lazy-jack-boom-bag

I have lazy jacks and know them well. I first found out about the Dutchman from this site, www.seabreeze.com.au/News/Sailing/Lazy-Jacks-or-Dutchman-The-argument-for-th

Never seen a boat with them, which likely says a lot

We had one on our Catalina 320 when we first bought it. Apparently they are popular in America. Didn't like it at all, it was a messy system compared to lazy jacks with a boom bag so we had it removed and replaced when we ordered a new main.

Thanks for that