Is the HP OmniBook 3 17 good for gaming?

Only for light and older titles. The Radeon 680M integrated graphics can handle casual games and esports at low settings, but not modern AAA games at high frame rates.

Can I upgrade the memory or storage?

The memory is a single 32 GB DDR5 module, so adding more means replacing it rather than adding a stick. The 1 TB M.2 SSD can be swapped for a larger Gen 4 drive.

Is the 17.3-inch screen good outdoors?

Not really. At 300 nits it is fine indoors, but the matte finish helps more with glare than with direct sunlight, where the image washes out.

How does it compare with a 16-inch laptop?

It gives you a larger screen and a full keyboard area, but the 16:9 panel is shorter than the 16:10 screens common on 16-inch rivals, so you see less vertically.

The laptop, its power adapter and the usual paperwork. It has no optical drive, so plan on downloads or an external drive for discs.

Is it heavy to carry daily?

At 4.4 lb it is light for a 17-inch laptop, but the large footprint makes it awkward in small bags. It is better as a desk machine you move occasionally.