There's been quite a bit of discussion about Apple's decision to use polycarbonate for the iPhone's case. Is the plastic on the iPhone 5c a sign that Apple's legendary focus on product quality is slipping? Absolutely not. Let me explain why.

We've been critical of some manufacturers' use of plastic cases in the past. And that's raised the ire of a few commenters here on our forums and on Twitter.

"Polycarbonate is just another word for plastic!" say some.

Polycarbonate is plastic, yes. But all plastic is not polycarbonate.

Polycarbonate has been used for years in the optical industry, to craft eyeglass lenses that are shatter-resistant and thinner than standard plastic lenses. Many of the sunglasses that are available use polycarbonate lenses; windshields on motorcycles, on planes and helicopters; some computer screens and e-ink devices - polycarbonate's use is myriad. It's a lightweight material that's easily molded into different shapes, It's a good electrical insulator and it's very heat resistant, too.

Apple's use of polycarbonate as a manufacturing material for the iPhone 5c is not unique in the world of smartphones. Nokia, for example, uses polycarbonate to make the cases used in its Lumia 925 and 1020 smartphones. HTC used polycarbonate on its One X; Samsung has used polycarbonate on some of its Galaxy models.

According to Apple folklore, Steve Jobs had the original iPhone's production retooled at the last minute because he discovered that when he carried a prototype iPhone in his pocket, the screen got easily scratched by his car keys. Corning worked overtime to produce Gorilla Glass to fit the phone instead.

And the big downside to polycarbonate is just that: while it's shatter-resistant, it scratches easily. That's why Apple has taken a step that some other smartphone makers haven't - they've lacquer coated the polycarbonate back of the iPhone 5c to make it more scratch resistant.

The iPhone 5c will scratch if you try hard enough, so it's still a good idea to put some kind of case on it that will protect it. Whether you go with Apple's cases or one of the many cases from third-party manufacturers now getting ready to flood the market is entirely up to you. But one way or the other, protect the phone.

The complaints we've had about the use of plastic-backed phones isn't in the use of plastic itself - it's in the build quality and the quality of the materials used. A cheap phone made of crappy components feels cheap and looks cheap.

So, to summarize: Yes, Apple went with a plastic back. But it's not just plastic. It's polycarbonate. Which keeps weight down, is shatter-resistant, heat-resistant and just an all-around better material. It's coated to keep from scratching. It's better.

There's nothing cheap about the build quality of the iPhone 5c. That's the difference.

Do you agree? Or do you think Apple's use of plastic was a mistake? Or do you think I'm splitting hairs with this polycarbonate stuff? Sound off in the comments.

If you're still sitting on the fence about the iPhone 5c, here are some links that might help you with your decision: