I was thinking the same. You do get a few bands now though who embody elements of both like Mastodon and Isis, who don't really sound old or futuristic. In many ways I think the best bands are the ones who follow the ethos of those bands rather than just nabbing bits of their sound.
Djent's now got to the stage that bands are using 9-stringers, and there are still barely any interesting bands around.
It's a comparison I kind of latched on to, to be honest, as there really isn't much I can compare Neurosis against. The ethos is similar, although in a way they're the polar opposites within extreme metal. Meshuggah are the futuristic extreme- that beyond-heavy tone in the guitars and the technology-based narratives, while Neurosis have a weirdly primal, tribal feel, with the chants and percussion.
Through Silver... was possibly the most punishing thing I've ever listened to. Either that or Meshuggah- they're roughly equal in brutality but Meshuggah pummel you nonstop, whereas Neurosis take their time and simply crush you. Such a great album.
I find that the vocalist sometimes doesn't quite fit them to the song- occasionally they feel a little off, though when he judges it rightly the results are brilliant. Glad you like them
I'm gonna dig properly into Through Silver In Blood over the weekend. I always like hearing a band who've massively influenced others that I'm into. Means I'll enjoy Mastodon and Isis' stuff that little bit more, the next time I listen to them.