In addition to being small, with SD card and 3.5mm jack, it is water resistant and has a removable battery. It is also one of the most robust non-hardened phones. It has an IR blaster too if it matters to you.
It was a time when Samsung was known for its gimmicks, the one for the Galaxy S5 is "Air View", where it recognizes your finger hovers over the screen. It is actually a good one, because it supports the "hover" targets in web pages!
Most people find it ugly though, and I tend to agree, but if you use a case, like most people do, who cares what the phone inside looks like?
My current Xperia 5 maintains battery temperature around 10°C above ambient during fast charging and since it easily lasts the whole day in the 30-80% charge regime, I believe it will outlast other components.