Do you prefer Android or iOS, and why?

Android is, in my opinion, the "best of what's currently available." Mind you, this does not imply that it is "good".

I dearly miss PalmOS and the Tungsten and Treo product lines, as well as the Psion brand. Those terrific PDA's had features that modern phones still lack. Conversely, I think modern phones come with a plethora of features that aren't really positive. But then, I'm not really a fan of the whole style where you can barely touch a device anywhere without operating it in some way. This is just my personal opinion.

The #1 reason why I would never choose Apple's products is that, while they excel at what you're supposed to use them for, their platform is way too locked down for my taste. As a device owner, I want the ability to customise stuff and install (and remove!) whatever the hell I want (including ads!), and Android delivers that in far greater measure than Apple.