The biggest difference is RAM compatibility. The new x470 do better with high speed RAM. I dont think XFR 2 and the revised Sense MI works with x370 chipset either, but I have heard some say that it works.
If you already have a x370, I would not get a x470 for a new chip. But if you are building a new rig and dont have the motherboard, I would spend a little bit more and get the x470. The improved memory compatibility alone is worth the headache.