I have to say that i prefer
Brooke, but I like them both as middle names, as a first name I think they are too simplistic and incomplete. Also they go really well with most names. Coincidentially I prefer
Skye over
Sky, the "e" on both names just adds something for me. But since they sound exactly the same I don't see much of a difference. Popularity wise I don't see it as a concern. I've never met a
Brooke or a
Brook, and come to think of it I've never met a
Skye /
Sky either.