I bought an iPhone 4 8 gig, and am in the process of buying another, both for my parents. They don't need nor want 4s for another hundred dollars more. It's a perfectly suitable phone for music they want to carry with them, etc. At least one of them won't even use all the features that it comes with. However, the iPhone 4 appears the only phone that wants to hold a signal where they live. The signal is fairly weak and it seems to hold onto it the best.
Thats the only reason why I would get one.. but then again I would probably get the free 3GS for them.
For only $100 more, why not spring for the 4S? Most likely you would be signing a 2 year contract.... so why not spend another $4.16 per month for two years for a better phone?
You can use the same argument for 16 -> 32 or 32 -> 64
I'm getting a $99 AT&T iPhone 4 for my mom. She won't use the video camera so 8GB is plenty for her photo needs and a few hundred songs.
I feel like the best deal would be the free 3GS on At&t... the 4 feels like too big of a downgrade for the price.
8 more gb, Siri, Faster processor, nicer camera > $100
I know that the 3GS is an even bigger downgrade... but you get the best the iPhone has to offer, iOS and all it's utilities, apps and with no software downgrade from the 4S but all for the price of FREE.