*sigh*
do you guys remember the Motorola Razr? Yeah, that phone was the #1 selling phone in the states for 5 years.
But ever since these androids started popping up, feature phones started to be forgotten and these smartphones dominated those tops spots. However, they don't last there for more than several months, and are considered old and outdated by the time that they are at least 9 months old, as newer and better phones start popping up.
The nexus prime will be great, no doubt about it. But it will soon be overtaken by another Android.
However, the iPhone 4s has no other iOS competitors. Because of so, it has no fear of competition excluding future iPhone models.
So, I would buy an iPhone.
At least each model lasts for more than 9 months.