Features are added all the time to generations of GPU's. Maxwell has been out for over a year and was the fastest GPU until the 10XX series. In fact even with Async, it is still an incredibly fast card and will be viable for quite awhile depending on your expectations. Nothing lasts forever.
Ok. I saw Time Spy review... and GTX 980 Ti is faster (GPU score only) than Fury X at Async enabled. Therefore, this thread will be deleted. I'm very sorry. Thank you.