My initial impressions of the phone were fantastic. Good size, an amazing screen, very responsive, IP67 rating, fantastic battery life, and a toned down Touch Whiz. I was extremely excited...but then I started really testing the camera.
First let me say that the camera is really good. Honestly, I think it's the best all-around shooter currently available on an Android phone. That said, I was hoping the new ISOCELL camera would bring the quality closer to what we see in the Lumia PureView cameras and to the camera on the iPhone 5S. But sadly, it doesn't. I spent a lot of time taking the exact same shots with the S5, the Note 3, and the iPhone 5S. Outdoors during the day, the S5 reigned supreme, with both the Note 3 and 5S close behind. Outdoors at night, the 5S was the clear winner with the S5 and the Note 3 providing similar results (with the S5 coming out slightly ahead between the two). Indoors, the 5S came out on top again in every lighting situation, both without a flash and with a flash. The S5 was slightly better than the Note 3 indoors, but really not by much. And all too often, both outdoors and indoors, things in the pictures from the S5, like the S4 and the Note 3, would like an oil painting (especially people and animals). Too much post-processing going on, especially with stabilization mode on for shots with lower amounts of light.
The camera is a huge part of a phone for me (both because it has to be for work, and I use it quite a bit personally). The S5 has officially been approved as a device we can use for work, so I was hoping to replace both my Note 3 and my 5S with it and only have to carry one device for personal and business use. But so far, the camera on the S5 makes that impossible. So, at this point I'm leaning towards returning the S5 and hanging on to my Note 3. If you don't need a top notch camera, particularly for low light situations, this is an amazing device that I completely recommend. And honestly, most people probably aren't going to be as discerning as I am about the camera, so there shouldn't be any issues.