How is Demi Lovato's new single Skyscraper?

I heard she released her new single on Tuesday How is it ? Has she changed since rehab ??? demi is a really great singer.. i think the most talented on disney channel.. she sounds like she's constipated in this song. she tries to go too high without switching to her high voice . its okay and i bought it but unlike some people,, it didnt bring me to tears.. i dont even know and i dont think anyone who doesnt know demi personally could say that shes changed.. you cant know just by reading an article online.