Actually I only got my 3GS two years ago, so that's exactly the same as buying a 4s now, which is what the OP is worried about. No, I wouldn't buy a 3GS today, but that's hardly the same thing. A 3GS won't even run iOS7. A 4s will. Saying it's silly to worry about having the newest tech all the time isn't the same as saying there's no such thing as out of date tech.
For the record, if I'm not impressed with the 5s or there's not a decent price cut on the 5, I'll be using my 3GS for another year.
out of date apple products struggle more from planned obsolescence than, say, Android phones do. At least with an Android phone I can find some sort of slim rom that maximizes performance and battery life.
Now I'm not saying that to troll; my girlfriend has a 3Gs on iOS 6 and it's painful. It's not the worst thing ever, but it's really, really slow, and the screen is laughable. Now, that might be fine for some people, but for the majority of people it's not.
Apple can say that they have less fragmentation than Android, because they do; but having old handsets that struggle on the new software isn't really something to brag about.
Back to the original point, the 4s is 2 years old now. Even the iPhone 5's hardware is old by now. If you bought the 4s for a discount or second hand, cool, but using an upgrade on a 2 year old phone is crazy, especially if you're posting here, since posting here shows some enthusiasm about apple products, and that enthusiasm usually manifests itself into the purchasing of newer products
As an iPhone 5 owner, I'm slightly worried that my 5 will begin to show signs of age with iOS 7. I can only imagine that worry would be increased with an even older device, with a smaller screen.
Just remember, by the time you're eligible for an upgrade, the iPhone 4s will be 4 years old. The iPhone 3Gs is 4 years old. Time does fly.
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and yes, return the 4s, for an S4 like you said, or an iPhone 5.
