Just to reply to Paul's comments, which are very insightful...
The last few years actually have seen some very notable improvements in technology, but they are subtle, as with many technologies the 80/20 rule sort of applies in that we got 80% of the way there very quickly and have now spent years tackling the last 20%. Mainly the improvements have been in tuning where the wheels are fast, the original wheels were nearly as fast as the current wheels, but only in a narrow range of wind angles, where the moden shapes allow the new 404 for instance to be faster than the 440 at every data point, but significantly faster in the 10-20 degrees of wind angle condition which is the most common real world condition. But at 25-30 degrees of wind, the 440 and new 404 are only separated by a few percent (advantage new 404) so the new wheels would only be slightly advantageous here.
But the main improvements (other than in durability, quality control, manufacturing, etc..) are in usability and range of efficiency. The old wheels were not only fast in limited wind conditions, but only with very limited tire width selection (<20mm measured tire width), something that today is possible with 20-22.5mm width tires, and in significantly more wind conditions. This increase in tire choice is better for everybody and lets you ride with more sane tire pressures for better RR as well as some comfort (very important for IM IMO) with increased durability and peace of mind.
We are asked the question quite frequently why the times of old still holdup so well against the times of today even though today's equipment is so much better, and the answer is that the old equipment may still be as fast as the new stuff in some very limited or specific conditions, but on the whole the newer designs will be faster (even if only slightly) 100% of the time. If you look at races elsewhere (especially the TdF) the times continue to fall and speeds continue to rise..but many of those events have conditions which are not as extreme as those in Kona.
Regards
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