HangOver, whoever you are..

I have looked a bit into this, and the differences are not that large on a beachcat. Depending on who you ask, you might get different answers..

In theory there is a small advantage to an asymmetric daggerboard setup but on a singlehander with spi you are overtasked as it is. Steve Clark reported trying asymmetric boards on an A-cat, without any significant advantage.
The C class cats are able to pull it off, as was the Formula28s, so it might be you need a certain size of the boat before it pays off.

Martin Schoon did a small study on the matter which is quite interesting. http://hem.bredband.net/b262106/Boat/dagger.html

For an A cat, ref. what "Uncle boat", Steve Clark, said..