I also don't see the introduction of a new boat from a recognised Formula boat builder that doesn't comply with the Formula 16 rules but is very close to them as something to be pleased about. You have to ask "why didn't they build a fully compliant F16, just as they have one of the recognised F18 designs in their stable?"
I know very little of Cirrus, but I would speculate that the reason they didn't build a fully compliant F16 is the same reason that the FX-1 is overweight - re-use of components and techniques from the bigger-selling F18s.
Do Cirrus not believe in the value of the F16 class?
The F16 class certainly isn't well established, but it seems that they're trying to have their cake and eat it using the "Open F16" rules. They certainly see some value in claiming conformance on their web page.
In fact I would go as far as to say that the door on 'grandfathering' other classes should now be closed. Rule 6.1 should be scrapped. I still believe that it does nothing to further the (genuine) growth of the class.
Yes - as I said before, the successful Datchet event didn't actually need or use the grandfather clause.
Paul