Hi wouter
we have been here before ;-)



Without restrictions we would allwas end in a armsrace.
Look at the 12er skiffs. 3 Riggs and even more sails.

It depebends on conditions you are sailing.
If you have to stay with your chosen sailarea (gib and mainsail or mainsail only) through the whole season.
Then IMO the uni would be faster than the sloop in a broad range of conditions. I think i depends mostly on the seastate. In waves the taller rigg moves more and the airflow will detach. Otherwise IMO a proper trimmed uni will have less windage, will therefore be more efficient even when overpowerd.