I'll boil down the difference between Apple iOS devices and Android devices.

I'd say that 99.9% of all iPhone customers buy the product because they're looking for that specific product - they want an iPhone/iOS phone.

In contrast, I suspect not more than 1-10% of purchasers of Android handsets make their choice based on the OS or product itself. Most of the volume is made up of people who just want a smart phone, period.

The story for tablets is going to be a bit different, but I think this concept will still play out to some degree.