I have an iPhone Air now and have no complaints about the heating. The thinness is worth the occasional heat and throttle down. Every time I pick up this phone, it just feels fantastic!
That doesn't matter, though. Battery replacement on iPhones is very common procedure and you'll need to replace both batteries eventually.
It was also so light that it felt safe to use it without a protective case. And not that expensive.
Solid, tactile, and just the right size. Mine finally got stuck in a boot loop earlier this year, but I keep it in my desk drawer, and pick it up occasionally. The mute switch (an actual switch, not a button) is still the best.
I find that I treat it very gingerly. Something in my mind expects it to be fragile; presumably because it's thin and looks like glass.