Because Android is powered by Google, you can do some really cool things. For example, in the GPS app, you only need to say the name of the place, and Google looks it up and programs the address. Also, can get real time maps and traffic updates, which may affect the routing.
Probably all will eventually have what the others have sooner or later. Also, the word is that there are the most apps for Android, since they are written independently, and do not need to go to a central place like Apple for approval. This may mean they are cheaper, too, but do not know the Apple marketplace, so cannot give first hand info. Just got Android about 3 months ago, and have been pretty happy, but everything has some glitches.
My old clamshell phone was easier to make calls on, and I find the touchscreen and having to poke through menus to bring the phone dialer screen up to be annoying.