Please don`t get me wrong here guys, NOT dissing the Hobie 16, but although it is a "one-design" class, it HAS changed over the years. You would not take a 1979 H16 to a National Champs and hope to qualify for the Worlds. This is not a bad thing, you can`t expect things to stay the same forever, when folks are discovering new ways to do things stronger, lighter and cheaper. Perhaps a 2025 Hobie 16 will be all-carbon, weigh 85kg and have a solid wing sail, and hoist a parafoil kite for downwind .
But seriously, the hull construction method has changed(I believe SOME carbon ??), the rudders are much better than a 1979 boat came out with etc. Sails are better too.
Just to give you an idea of the differences, H16`s used to be built under license in Cape Town, they were good boats but the top SA guys all bought French boats, which dropped the bottom out of the market here. Some of the top guys would buy a French boat, but use bits from the South African platform (lighter aluminium), the SA mast and sails (which are about a square metre bigger ????).
I chatted to Sean Ferry just after he won the Worlds - said one key reason the other SA guys struggled to sail the supplied boats was because they sailed with SA sails in their build-up to Worlds, whereas he sailed with the sails supplied by the French H16 builder, so he was used to the sails, the guys who had sailed with SA sails all season could not get used to having "less power", they were a lot closer to him all season than they were at Worlds.
Although Hobie claim that they provide the closest One-design racing experience, it only really holds true if you`re all sailing the same year model, why else would the top guys replace their boat every 2-3 years ?
The Dart fleet is much closer to the pure OD concept - I bought a one-year old Dart to sail the Worlds, the guy who sold it to me needed cash, he then bought his hulls separately from crashed boats, found the other bits, had a spare mast lying around, bought some fairly well-used sails, and was leading the Worlds after 3 days, eventually finished 12th, while I found myself in 68th with his "new" boat. At the same event Johnny McGillivray sailed a faded red boat built in 1979 (not kidding) into 10th place (and he`s a Hobie sailor who had not sailed Darts before the Worlds )
One-design racing offers you the opportunity to all sail boats that are as close as possible to eachother, not even the Laser class can claim that all boats are identical.
The bottom line is that, by losing 20lbs, Hobie have embarked on a clever marketing strategy, ensuring all serious racers will buy new boats, which they would have done anyway. This will release a good number of used boats into the market, good for sailing, good for Hobie 16 class growth, but you have to accept that if you`re not on one of the new boats, you will have to sail a little bit harder to get to the top.

No Hobie sailors were harmed during the writing of this post - just my honest opinion.