With every device release manufacturers improve displays in a number of ways. 2011 ushered in 720p displays, 2012 followed up with 1080p displays, and now we're seeing the launch of the first 2K display phones in 2014. While the Samsung Galaxy S5 isn't a 2K display that doesn't mean there haven't been improvements in the display technology used in the device, as being the same 1080p resolution as the Galaxy S4 and Note 3 doesn't necessarily mean it's going to have the same disadvantages or advantages as those phones. Traditionally AMOLED displays have been lauded for their high contrast levels, delivering super deep blacks (Shadows) and crisp highlights on the picture without the bleeding that can be found on LCD displays. Samsung fixed this problem with the Galaxy Note 3, allowing it to reach up to 660 nits brightness level in direct sunlight, and it looks like the Galaxy S5 will be sharing that same great quality. Another issue some people have with Samsung's AMOLED screens in particular is the extreme color saturation that's found with most of the display modes. Many complain about colors being a little too rich, and it looks like Samsung has answered by giving slightly toned down colors when using the Adapt Display mode when compared to previous Samsung AMOLEDs. Movie mode is still the kind of color accuracy though, as it has been on previous Samsung AMOLED devices, so no surprises there.
What's really interesting is that Samsung seems to have allowed the auto brightness setting to bring the screen to a higher luminance level than the manual slider allows you to. When in direct sunlight the Galaxy S5 effectively kicks on torch mode, maxing out the brightness beyond what you are manually allowed to set it to. This is probably to help save the screen's lifespan, as you normally won't be using the phone in the sun 100% of the time, and leaving it at that level would probably cause burn-in or other non-desirable effects. In terms of sharpness of the display it seems on par with both the Note 3 and S4, and likely uses the same diamond pentile display found in the Note 3 to mask the fact that it's a pentile display in the first place. Being a smaller screen than the Note 3 would also produce a sharper image inherently, and since it's likely diamond pentile like the Note 3 instead of matrix pentile like the S4, the overall quality of the image will be higher anyway. While the pictures below aren't scientific comparisons by any means, they give a good representation of what you'd see from the screens when comparing them side by side right in front of you.