Thats awesome Clarity.....
August is HOT and HUMID and slow .....Lots of shops/vendors closed down for slow season..(with exception of ATI week-) but you still have the wonderful beach and cliffs to jump into and cool off-and hey your in Jam...what more you need.
I would take the JUTA..its a piece of cake-8 hrs too long to be hangin out at MBJ (even with the new fancy lounge area they have) I'd get a head start and maybe have some kind of lunch/dinner planned out for when your family gets there...
Or take Clives-I've used them many times- a little more $$$ but like Gerry said if your the only one-off you go...
and yes ,it raiins a little bit each afternoon-but its lovely ,warm,tropical rain that does not last long...