It all comes down to a matter of personal taste and outlook on sailing. Someone who wants to cruise far and wide should be more concerned with comfort and safety than with the boat''s speed rating. Someone who plans to race should probably not be too concerned about the boat''s sea-kindly ride.
The IP''s appear to be made for use over vast distances. Based on what I''ve seen and read, they seem to be well made for that purpose. I seriously doubt that when everyone aboard arrives at a distant location a week or so later that any will say, "I wish we could have had a rougher crossing to possibly save some time." :^(
Lastly If ''speed'' is your thing, then perhaps you should consider a power boat. Now that''s a group of "Type A''s" if I ever saw one. It seems to me that sailors are mostly "Type B''s" with some having "Type A" tendencies. ;^)
Happy sails to you ~ _/) ~