Not Much
Jim I have a 2001 C380. I recently went to the Sydney Boat show. There was a 387 and 400. The main difference between My 380 and the 387 was their seem to be more room the the main saloon area, I think because they had reduced the Nav table and just better use of space, they also made the Aft cabin a lot roomier. Apart from that there was no real noticable difference. The 400 was beautiful, I have never seen a 390 and cannot really comment. I would definately go for a 400 if I was looking at a 390. Whats the difference in Price? I'm saving my pennies for a 400. The 380 is a great Yacht and I have had no problems at all with it, she sails great and is excellent extended cruising, A real strong boat.Good Luck