One of the features I love the most about Cillian is his beautiful bone structure and his jaw muscle flexes so when he has a bushy beard, it completely hides those features and I don't like that, I just don't think it looks good on him in my opinion. However I do love when he has a little bit of facial hair, for example on Perrier's Bounty, I think it looks so sexy on him.

But I think he looks his sexiest when he has no facial hair, his beautiful bone structure is then more defined and gorgeous to stare at ;)