4k drives: benefits and models?

[Louis-David Mitterrand]

Hi,

I've been reading the "4k drive" thread with interest and I have a few
questions:

- what are the benefits of these new drives? Speed, temperature,
  reliability?

- what specific HD models are truely 4k for purchase right now? I'm on
  the market for a bunch of 2Tb drives, what is a good choice?

- what options do I need when creating my raid6 array and xfs filesystem
  to fully take advantage of 4k sectors?

Thanks,