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

It is usable for gaming but noticeably soft for text and spreadsheets. If you sit close and do office work, a 24-inch version or a higher-resolution panel is the better fit.

Does it work with FreeSync and G-Sync cards?

FreeSync works with AMD cards over DisplayPort. Many Nvidia cards also run it as G-Sync Compatible over DisplayPort, but check your card's support list first.

How is it for fast shooters?

The 180 Hz refresh and 1 ms response make it responsive. Expect some dark smearing from the VA panel in very fast pans, which IPS rivals handle better.

Can I mount it on a monitor arm?

Yes, it has a VESA mount pattern, so you can swap the included stand for an arm or wall bracket.

The monitor, its stand, a power cable and HDMI or DisplayPort cabling depending on the bundle. Confirm the cable type with the seller before ordering.

Is it worth it over a 24-inch G3?

The 24-inch version looks sharper at the same resolution and is easier to drive. Pick the 27-inch only if screen size matters more than pixel density.