Todd,
actually the mast was the same height. The N/A's came in about 92 or 93, I believe. The N/A had a larger main which ended up needing the internal extra diamonds and longer spreaders to keep the mast in one piece. Some of the original non N/A models had a smaller, self tacking jib on a straight traveler track that didn't work all that great. Sometimes I wish I had a 6.0 instead of my N20. It's a smoother ride by far.