Considering only the 12 competition days that all three classes were scored...

The average winning speed in 18m class was 148.9kph (92.5mph).

In 15m, the average winner was 4.6% slower than 18m at 142.0kph (88.2mph).

Open class winner was 0.8% faster than 18m on average at 150.1kph (93.3mph).

Isn't it interesting that all of that new technology in open class had so little actual benefit in the final analysis?