I think the comments above cover most of the reasons why the Drascombe lugger is not as fast or close winded. Bear in mind though that Jeff and Claus are BayRaider owners to-be, so they are bound to be biased!
In summary, the sail plan is fairly small for the weight of the boat, and she also has a short waterline length, compared to her weight.
The flat non profiled centreboard really does nothing to create the dynamic lift needed to go to windward well, and the way the sails are sheeted, ditto.
Having been hit on the head by a block shackled to the end of a flogging mainsail I definitely prefer the sprit boom arrangement as seen on our boats, as the boom is high above heads when seated, but you dont have the high sheeting loads associated with boomless sails. It is also far safer and more controlable off the wind. The twist set up in boomless sails as you let them out can set up an unnerving roll downwind, though the lugger has plenty of weight in the hull so this is less likely to happen.
If you would like to know more, please ask.
Best wishes,
Matt