Love the original recording with Ian Gillan singing the part of Jesus. In fact, I've got a strange sentimental attachment to it. There are parts of it that really move me. I was born in 1971 and my parents told me that it was on constant rotation when I was in the womb. I've always wondered what the psychological impact of that was on me.
As to the question of "blasphemy", I wouldn't use so strong a word. It definitely emphasizes the humanity of Jesus and ends with the crucifixion, not the resurrection. So, some Christians might find it a bit lacking. But it was never meant to be an evangelistic tract.
I enjoy it for the great music. IMHO, it's the best Andrew Lloyd Webber ever did.