The preview is pretty epic, so I will probably buy your album. (if i do it will be the first album i have ever bought).
Also it appears that F3official is trying to say that this preview did not give a headache, instead it's awesomeness removed a pre-existing headache. Music that can cure headaches is in short supply, and can be more effective than taking medication that is supposed to have the same effect, and without any negative side-effects that medication may have.