Really big - no
small advantage - yes

Mainsheet: you can have a smaller diam line running through the blocks... makes for faster release of the main, and a larger diam where you hold the line (makes for easier grip)

Spin Sheet - I don't see any value except maybe having a thinner diam where the sheet attaches to the clew (to make getting over the forestay a little easier)

Halyard - hmmmmm - can't see why / how this would be any benefit / value - but maybe someone else will see value here