I think the X means it has auto overclocking (xfr), maybe someone else can clarify that! I'm getting the non X as I am happy to tinker with the bios settings to overclock.
Is the 1700 (non-X) not going to be a 65w CPU though? Dunno what that means for OC'ing yet, but I assume not great. Probably decent for lower power though.
My use will primarily be encoding, so moooaaarrrr cores is better for me, and if they are really as good at multi-thread applications as has been leaked, I'll be a very happy bunny. I can forgo the drop in gaming quality, since I only just bought my first new GPU ever (and first dedicated GPU for about 5 years), and that was only really because I knew Ryzen didn't have integrated GPU.