This is the monitor for competitive gamers who care more about reaction speed than picture detail. At 280Hz it refreshes nearly five times faster than a regular screen, which means smoother motion and less delay between what you do and what you see. If you play shooters or fast MOBAs, that edge matters.
The trade-off is resolution: 1920x1080 on a 27-inch screen looks soft compared to sharper 1440p panels. Text isn't as crisp and you'll notice individual pixels if you sit close. In fast games you won't care, but browsing the web or working in Excel feels less clean. Most people find 1080p better suited to 24-inch screens.
The HDR label is a box-check feature that doesn't actually make games look better. Treat this as a fast gaming screen with decent colors and you'll be happy with what you paid.