[hdmkv]

Hello, new user here.. I just ordered an X10, can anybody point out where do I begin?
What player should I use, what firmware etc. The thread is really too big.
Thank you.

I'd start with f/w 1.4.4. Then, install ZDMC based on Kodi 17.1. Enable external player option within ZDMC.

Also the X9S will play 3D iso? And work with surround sound?

Yes and yes (including Dolby ATMOS and DTS:X). Two of the main reasons for appeal of Zidoo, along with 4K and HDR support.