What quality issues? I haven't heard of ANY cases where a scratch/scuff due to the carelessness of the owner (sorry but that's what it is) caused the phone to not function 100% as advertised.
It's ironic that when the Android vs. iPhone debate occured prior to the 5 no one ever brought up how durable the iPhone 4 was as a major selling point (perhaps it had to do with dropping two slabs of glass, who knows?). Now, all of a sudden it's all that matters. People scream it's a "Gate" and that it's ruining resale value...
Here's a hint: You won't be able to keep ANY phone in "mint" condition if you use it for a year or so without a case. If resale value really keeps you up at night, you are being absolutely (insert insult here) if you don't use a case. I don't believe the people who say they have used a phone for a year without one and it has remained perfect.
Not to mention that thus far, the impact on resale value for a "nice" 4S vs. a "mint" 4S has been (in most cases) less than the cost of an Otterbox Defender ($50). Resale value is NOT a valid argument. It's an excuse the hyper-anal, OCD folks use to try an justify their behavior.
There is no "quality issue". If you take care of your phone it will remain perfectly usuable and quite nice to look at. Flawless? Nope, but you're lying to yourself if you think ANYTHING stays that way after normal use (especially a device that goes everywhere, including bathrooms, with most people).
Enjoy your smartPHONE... that's all it is...