Difficult question to answer
The purpose of either mast or boom furling is to make something easier on a sailboat. Stowing a sail can be done in the mast or on a boom--each has its own unique problems and each probably saves the sailor some energy and/or time.I've had a in-mast furling main for 6 years and the only problems I've had was that the continuous furling line came apart and once when I had a friend help me install the main after an inspection, he did not put it in the slot and it blew out in a heavy gust. My fault for not checking it.A furling main in the mast is easy to pull out and to reef and to furl. Its only drawback is that you loose about 30 percent of your sail. However, if you have a taller mast, hence a bigger main, you gain some of that back. Another drawback for me was to learn how to sail the main. I had relied on battens for so long that I had almost forgotten how to shape a main. An excellent reason for in-mast furling is the infinite possibilities for reefing (or furling so to speak). You have almost total control.I have sail one boat with boom furling. It too gives you many possibilities for reefing or furling. A negative for us older sailors is that you still have to winch the sail up, but it is a doable activity. Another problem is that you have no control over the outhaul when reefing. I suspect some sailmaker will solve this problem soon if they already haven't done it. A major advantage to boom furling is that you can have battens which help shape the sail. If you had an electric winch, this might be the best of all worlds.The biggest problem that I see with either in-mast furling or boom furling is that many people have not learned yet how to shape their sail using new controls. It took me several years to break my habits of using traditional thinking of shaping a main sail. It is my opinion that you will have to learn new ideas of sail controls and try new techniques using the furling lines as sail controls beyond just furling your sail, One thought that I just had was with a furling main you still need a mainsail cover. At the moment I'm in love with my in-mast furling main. I sail well, tend to reef faster than I did with a traditional sail and I tend to use my sails more in a cruise because they are easier (for me) to use. I am an old sailor but I still like to sail. This feature lets me do my sailing and cruising.My best to you,Les