First impression is a 5. But I strongly suspect that it will grow. I haven't heard a DT song yet that revealed it all on the first go, it's simply not that kind of music. That's part of the attraction to me, that I keep hearing new and awesomer things the more I listen to it.
But to be fair, as much as I consider myself a fanatic when it comes to established DT classics (I'll defend the snare sound on IAW or the millions of notes in any random solo tradeoff to anyone...), and I won't budge, I have to be fair and say that right now, after my first listen, this new song didn't sweep me off my feet.
Now let's play it again. Another 10 times or so.