I love my S4, which is 2 years old, and will regret trading it in as it does everything I want, and more than I see on Apple products which are just coming out now!
The Samsung S4 was the first phone with a MEMS hygrometer, a fact that most people do not know.
And a Samsung S5 had a Sp02 sensor built into it. . . but no medical professional I spoke to could figure out a sensible use for the bleeping thing. And how accurate can a hygrometer measure atmospheric humidity after being kept in your hip or shirt pocket next to a sweating human body? Not at all accurately I am reliably informed.
In other words, these sensors are added in because some Samsung engineer though "Hey, that sounds cool! Let's toss that in!"
They are added to the specs list for the benefits of the geeks who count the numbers of cool gadgets their phone has, not whether they are useful or not.
"You've got to start with the customer experience and work backwards to the technology. You can't start with the technology and try to figure out where you're going to try and sell it.....we have tried to come up with a strategy and a vision for Apple, it started with “What incredible benefits can we give to the customer? Where can we take the customer?” Not starting with “Let’s sit down with the engineers and figure out what awesome technology we have and then how are we going to market that?” And I think that’s the right path to take." — Steve Jobs"Perfection comes from how many things you can take OUT." — Steve Jobs.