I'm not sure where the Garden State Parkway comes in for your usual route? The turnpike and the GSP are not the same road....
At any rate, I would generally also go I-84 to I-81 and take I-81 south all the way to either I-77 or I-75, depending where in Florida I was going. For western MA, it might make more sense to take the pike/I-90 to I-88 to I-81. (I-88 has a reputation of being unbearably rough, but that has not been my experience. Much of it is quite nice at the moment as they've done quite a bit of maintenance/repaving over the past year or two or three and several portions are basically brand new.)