Without getting into the hull form issues (high drag, shallow draft, beamy with beam carried to the ends of the boat) or
rig proportion (a cutter
rig that depends heavily on large over lapping headsails and for which the staysail is too small to balance the main except in in extreme conditions but which is necessary for the sailing ability of the boat in moderate conditions) which have been covered in other places, there are a wide variety of details on the IP and design features that I think make them less than ideal as an offshore cruiser. These would include:
-The IP 38 post hung rudder that is as deep as the keel bottom fully exposing the rudder post to damage.
-The propane locker in the side deck where the drains/vents are underwater when sailing heeled.
-The use of the Hoyt boom which tends to leak around its swivel in heavy going.
-The ballroom sized cabin decks without footholds.
-The general lack of sea berths and the layout of the double berths on the boat.
-or even small goofy thing like the use of the cheapest
Ronstan solid sheeve blocks.
Jeff