had a nice lady at the ramp yesterday say, "that's a pretty small vehicle for such a big boat, ever have trouble?" i was like, it's AWD with a HEMI ...plus it has a Class IV and trans cooler.
my fave ramp is relatively steep: sitting on the ramp incline, i use the hand brake, of course. to pull the boat out, i tap the shifter down to a low gear. holding the brake pedal with my left foot and easing into the gas with my right (just like a clutch, to prevent that little coast backwards). after i climb out, i tap back to the high gear. always looks smooth and i've never had a worry. also, in the beginning i did (due to newbie caution), but i've started using the Tow/Haul feature much less since it's so flat here. it's certainly no diesel F450, but i've had no complaints or issues.
i bought my Cherokee specifically as a boat towing vehicle - i'm just not a pickup sort of guy (everyone i work with has a pickup truck like a bad cliche). with that in mind, i took my time to find a well-maintained WK Limited with the 5.7L and Class IV. however, there are people everywhere towing 23-24' boats with Wranglers - i own one of those too and it looks really tough, but i don't think i would use it except in an emergency. my point there being, a properly set-up Grand Cherokee will work just fine. oh, and the previous owner of my boat towed it across Florida with a Kia Sorento! 3500lbs towing capacity.