Well,

The world of big expensive monohulls are moving to portsmouth racing... They call it by a different name...
IRC I believe. AYC SFYC and all of the major US Clubs will be using it next season for the major big boat events.
Things like the Race to Bermuda, Key West RW,
You know... small insignficant events that you gather millions of dollars of boats for racing!

What is it. A single number time on time rating system... eg... the same as using the DPN in portsmouth.

The essential difference is that they use a model to predict boat speed based on the features you are using on your boat... AND a judgment factor for boats that appear to be rule beaters to compute your rating.

Oh yeah... its adopted world wide ( We are slow to wake up in the US)!

Now, I am sure that they would love to get 10 Farr XX's on the line... but they are a pain to trailer and so they go portsmouth racing most of the year.

I think that if your sailing skills are at the Olympic Level... you hold out and go one design racing... otherwise... just go racing.... the guys with 1/2 million plus invested are going Portsmouth(IRC) racing as well.
Finally, All of the vetching about the arms race in F18 sails and Tornado sails... pale in comparison to the arms race in these big mono racing boats; supposedly, this IRC rule will generate fair ratings to account for the race and grow the sport by getting participation from lots more sailors.