I sailed on a IP 380 in Maine this past summer and I loved it. The boat does need at least 10 knots of wind and is made for 15-20 knots where you can set the sails and the autopilot and feel like you are in your own home except you are on the water. It does need wind. We did get it up to around 7 knots on a beam reach.
Though I loved it I am, myself, purchasing a Dehler 34 because I will be doing more daysailing and maybe some racing along with weekend trips. The boat will be quicker in lighter winds.
I would base your decision on your experience, full keels are very forgiving boats, and use, IP''s I don''t believe will make good daysailing boats.
Frankly if your looking to cruise the Carribean and are not in a hurry I think you, and especially your wife if you have one, would be very happy and secure in any IP.