I don't care if Gobolord found it great (arguments stand and fall on their own - so I don't care who said it). I wouldn't use Thalia, I think she looks terrible.
I'd need to splash white to fit her in my deck and I could run
thorn of amethyst which does the same thing and I wouldn't need to splash white. Not only that, but I could put more than one thorn of amethyst down whereas I could only drop 1 Thalia.
So if everyone is being serious now and telling me that somehow Thalia is better than thorns, I'd really like to know why.