This Particular 280hz is Still not Ready for the Big Leagues
Got three of these from two different suppliers and they all flicker; used varying high-speed cables, different cards, and even different computers. If you don't mind the occasional artifacting or flickering, then it's decently fast. From the frame timings, it also doesn't hit a true 280 refresh rate. Wait for the next generation panels to mature. As of 2022, I think the stable limit is at 240hz.