In terms of weight the newer you go the lighter you get. My boat is an 86 and it weights about 10kg over the minimum weight but my boat wasn't used much. It all depends on how the person looked after it and how offen they used it. If its for a learning purpose it is a great idea to get an old one then move to a newer one but if you know how to sail and want to race go newer. sorry i cant say much more on the topic but i dont make the boats.

Jules