W..
Sorry not up to-date with northern style cats..

But it still is a huge stretch to believe its possible and a fair rating!!!

The Tornado in classic rig is rated in Au at 69 on the VYC yardstick < http://www.vic.yachting.org.au/default.asp?Page=1352&MenuID=Handicaps/1023/0 >with the "big rig" holding a reliable 66 rating.. (18teens are 68.5) The A is reliably rated at 71.5.. Interestingly the T4.9 sloop has a "reliable" 74 rating as opposed to a "probable" 76.5 for the T4.9 cat..

What the European rating asks us to believe is..
That the cat rigged kite-added T4.9 has become far faster than the sloop with kite.. Not only this but.. Now far faster than the Tornado in classic rig or even with one that has an added kite thus faster that the A...

Based on the http://www.schrs.com/ website ratings we should expect to see the F16/T4.9 with genacker holding a VYC rating of cat rigged 67.5-68!!! Thus roughly equal to the T5.7 with spin (67.5).. Like I believe that NOT!!!!

If you believe this I have a bridge for sale in Sydney going cheap..