I'd like to add my tuppence . Good well maintained in masts system like all gear
rarely give any trouble. The vast majority of jams are caused by too little clew tension on furling and this generally results in not being able to get the sail out rather then in the other thing that few sailers understand is the processes involved to unjam an in mast. ( probably because they rarely jam) .
Yes everyone accepts that battened sails
are more efficient, but in most cases properly designed in mast sails
are more then adequate . If this was an efficiency argument we'd all be using rigids
In my opinion having owned both battened single
line reefing system and in mast, there's a lot to be said for in mast. Ive have lots of problems with battens and if was to buy another conventional sail, I'd avoid full battens . I've yet to be on a conventional production boat where single
line reefing doesn't require a trip to the mast to ensure the sail is ok and this means that one man watches are problematic especially art night. Where's on in masts it rarely requires it.
It's entirely possible to reef in masts downwind. Went across the Atlantic on and in mast and we had no problem reefing at 150 degrees. ( reckmann in mast)
Modern materials have also removed the sail weight issue and there are also a number of systems for supporting a small roach as well ( I like the air battens idea)
To say that experienced sailers avoid them is quite wrong. amels, ovnis oysters , HRs etc are all bought by experienced sailers and lots are sold with in mast.
The other thing is far less string in the cockpit
. Especially as in my view modern main driven boats ( and this applies to cats) need three reefs
in the main to control the speed ( this is particulary true of modern French production boats). And this results in more string. The best reefing is double line reefing but now there's six pieces of string not to mention all the clutches. In fact a fully car based three reef main system is probably more expensive then in mast.
I really think dogmatic opinions are best ignored. Each system has pros and cons. Go with whatever suits you