IN BOOM MAIN SAIL FURLING
The pros and cons? This comes to my mind re. in boom main-sail furling systems:
You can "trim" your boat with a rolling system as if you have numerous reefing points.
It stores the sail protected and neatly inside the boom.
It is really easy to hoist to the exact size you require for the conditions.
Works well beside a separate track for a try-sail/storm sail.
Minimum weight aloft.
Can be used with a "racy" fractional rig, but usually best with simple masthead systems.
It is far to expensive for "what it is".
Depends on a "good installation" to work well and trouble free.
The "descent-rate" of the sail must be precisely controlled, maybe with a adjustable halyard-brake. You cannot let it "free fall" down like when you use lazy jacks.
The boom must be at a pre-set angle to the mast or the sail will roll upp unevenly, much like when you try to roll back two yards of toilet paper!