sboardcrazy said..
Why do they now have wider luff tubes? I assume it's for aerodynamics..?
Basically yep... You can get a much deeper sail with a wide sleeve without having a big nuckle at the front of the sail which is slow. Generally the wind ranges on race sails has increased immensely since the switch to wide sleeves a while back.
Now the sails have zippers around the booms and tighter mast tip entries at the top of the sail so they do hold the water out a bit longer than older sails so you do have time to get them out of the water after a crash... but if you leave them sit for a minute and fill up with water; they are a nightmare to uphaul...yep!
Overdrives have less sleeve width than a Reflex and is a good happy medium between performance/ease of use.