Android is nice, the data hunger of Google bothers me enormously,. Apple is certainly unsolicited fetch data also, but they do it at least not quite as plumb or be caught.
Windows Phone with its synchronization mechanism (mandatory use of MS cloud, data need only to then get onto the smartphone to the cloud via I-Net) a disaster.
By design, the iPhone is the most beautiful 3 for me by far. Run as a 3GS with the current BS 6.3.1 all apps. Since there with 3G and his BS 4.3.1 before problems.
Wen 3.5 inch display does not bother (remember, the iPhone 4 has the same screen size, but in my eyes is ugly and considerably more expensive) which is well served with the iPhone 3 GS. I personally can not do anything with the giant lobes.
Battery power is in my, admittedly not as intensive use, more than adequate. 3 days without charge go loose. That's significantly more than the 3G.
Use the Apple OS also convinced. It happens to be the granddaddy of other smartphone OS. Synchronization with Outlook is thanks ITunes also made jiffy.
I use the phone only for business, ie no music, no SMS, no Facebook and other. Calls, calendar, e-mails, sometimes use from time to time an app navigation and rarely look what the Internet. For the 3 GS is perfect.
This one has a design icon in the bag is a nice gimmick on top.
I do not belong to the Apple disciples. Prices are raised in my eyes with the current models. Who is, however, willing to lie not quite 300 euros for a nearly 3-year-old model, which is a simple to use, thanks to the current BS rewarded fully usable and send Smartphone. I hope that this smartphone will accompany me for a long time.