Cubase 8.5 + 12 Core Refurbished Mac Pro?

Hi all,

Im on cubase 6.5 + imac 2011 + OSX 10.7.5

Its time for a new setup.

Im thinking of this:
https://www.ipowerresale.com/buy/mac-pro/346-12-core-westmere
2012 refurbished 12-core 3,46GHz/64 GB Ram/OSX 10.11

Anyone have any experience of a similar setup?
Does cubase work well with 12 cores? How much RAM can it use (can’t find any info on this).

Are Steinberg responsive to their customers nowadays or how is the situation?

Any input is appreciated.
Thanks.