Is Sweeney Todd alright to see??

I dont know whether to see Sweeney Todd or not. I have seen TONS of R rated movies, such as The Black Daliah, Saving Private Ryan, House Of Wax, and alot more. I watch alot of gory and violent shows, such as 24 and CSI. I am alright with any amount of blood in movies and any amount of murder is fine. Apart from that, is there anything else really bad in that movie??? I am trying to convince my mom to let me see it, concidering i am underage. Is it really that bad????????? Please respond ASAP! Thank you!!!