Invision's smilies are too big and I don't like to mix them with vBulletin's.
I agree that smiley is annoying and it especially annoys me as a post icon.
On my
forum's smilies I put a toothless smiley in place of the default big grin, because I thought that toothless smilies were beautiful too and should not be discriminated against or considered any less beautiful.