Yes, the iPhone 5 is the best phone ever released to mankind. It's a masterpiece in regards to everything from its design to its user interface. You can't go wrong when you go with the iPhone 5. That's why it's the best selling smartphone on the market as well. Apple knows what it's doing.
The iPhone 5 is not the best phone yet. In fact, it is far from it. Apple has yet to make a phone that doesn't shatter into bits when dropped, and while the iPhone 5 improved this factor it did not solve it or even bring it up to par with other phones. I think that Samsung is currently leading the smartphone war.
Making a phone longer isn't going to make the phone better. Making the phone a bit wider AND longer would have been a huge improvement. With phones like the Galaxy S5 out there, this phone is a complete disappointment. The iOS also angered a lot of people, so I think we should hold off on the best phone title.
There is one big issue when it comes to that of iPhone and it deals with the battery life that is in them. The iPhone 5 along with other phones that the Apple company has come out with have very bad batteries for them. There needs to be more development with the battery.