Rev. 1.1 adds a better heatsink on the VRMs afaik. It might also add Zen 3 support out of the box, i haven't found any info on this. In other Gigabyte X570 boards though, rev. 1.1 adds a Thunderbolt header. At first i thought the Gaming X had this feature too, but i looked it up and sadly it doesn't. Nevertheless, it still is an ok board with full pci-e gen.4 support on all slots with Ryzen 3xxx and 5xxx series.
Laters dude