Agree with Sailmc that it''s not so much anti-IP sentiment as some direct discussion of how they perform compared to other boats. The IP may be perfect for your coastal cruising and Caribbean plans. Other responders to this thread make the point pretty well that it''s all in what you''re comfortable with and want in a boat. IPs are solid, dependable boats, and you pay for that of course.
I also think it interesting that you included the J-42 in your list of candidates. I spent some time on that boat in Annapolis and had a nice chat with Rod Johnstone,the designer. Even his cruising boats make few concessions to the usual amenities one expects of a cruiser. The J''s are SAILboats first and foremost and don''t pretend to be condo queens. No wide ass sterns on them! Interesting to compare the J-42 to an IP if nothing else, even though it may make your head hurt from the differences.
Good luck with your decision.