Review: Apple iPhone 5s
Top message: Premium device? by Poison Ivy
Replying to: Re: Premium device? by Zpike
A "Premium" device should have a casing that's sufficient to make the device last (polycarbonate is a good material for this) and a software that sums all the technological improvements.
Having a metal case is not good for a smartphone, as metal is a great heat conductor and may lead to the phone to overheat (damaging the battery and so), plus, it also blocks/weakens some wireless signals. Besides the thing with sealed battery, inexpandible memory and so...
So that subjective "Premium" feel of the iPhone's case kills the other part, which is performance. iPhones are limitated in comparisson with other devices.
You should also take in mind that there are protective cases you can buy for a phone, so if there's a phone that you like because of its specs but dislike the case, you may purchase another case that fits your needs. Most people with iPhones end up buying a case for it, making the whole "Premium" feel of the original casing senseless.
If you base solely in the casing of a device to determine how "Premium" is it, you might as well buy a cheap feature phone and build a metal case for it, that seems perfect for you! (plus, cheaper)