I have no objection to sailing F18s even, but giving time is too much. That's a class killer for sure.
The difference in SCHRS rating between a single handed F16 and a F18 is less that 1m30s for an hour racing. Quite minimal. Duo F16 are giving time to F18, 18 seconds for each hour of racing.
So the difference in rating between a single handler F16 and a dual-handler one is *more* than the difference in rating between an F18 and an F16...
I'd say it's fairly close. And I think overall F18 sailors are better than we are, we need to improve to catch them up.