Ok, here are some pro's and cons:
As far as I can see, with any fractional rig and the apparent wind
behind the beam, you are goind to get chafe. Fractional rigs have swept back spreaders, which will chafe the mainsail
if let out too far, and the mainsail
blankets the foresail anyway.
So, (as Maxingout says elsewhere) for downwind routes - trade wind
sailing especially - a 'no--stress' sailing option is to pack away the mainsail, and just use the head
sail. As a fractional rig only has a small headsail, then you need another one (gennaker, spinnaker
etc) to help.
With a masthead rig, you normally have a larger foresail and probably in-line spreaders, so more (easily handled) downwind power, less chafe.
(And the BB, at least, points as well as any other mini-keel cat, and can deploy two large furling
Finally, a large roach, fully battened fractional rig mainsail is a HEAVY thing to have aloft - you start to need electric
winches or multipart mainsheet tackles. (and try reefing THAT without luffing up, and increasing the apparent wind!)
My opinion: for in-shore, busy areas, (and charter
use) a fractional rig is easier to tack and probably appropriate. For longer distances, and where you cannot predict the weather
, the masthead/BB approach is better.