Is 1080p sharp enough on a 27-inch monitor?

It is usable for video and casual use, but text and fine detail look softer than on a 24-inch 1080p or a 27-inch 1440p screen. If you read documents all day, a higher resolution is the better pick.

Is the 100Hz refresh rate good for gaming?

Yes for casual and light gaming. The 100Hz panel and 1ms response time beat standard 60Hz office monitors, but there is no adaptive sync listed, so fast competitive play is better served by a gaming monitor.

Does it have built-in speakers?

No. It has a headphone output but no speakers, so you need headphones or external speakers for sound.

Can I mount it on a monitor arm?

Yes, the stand is removable and the monitor supports VESA mounting, which also solves the lack of height adjustment.

How does it compare with a flat 27-inch IPS monitor?

The curved VA panel gives better contrast and a more immersive feel, while IPS rivals offer wider viewing angles and more accurate color. Choose this for contrast and curve, IPS for color work and shared viewing.