I carry an iPhone 4s for work, and my personal Android, a Motorola Droid Razr Maxx.
All else being equal, the Razr Maxx wins hands down for screen size alone.
The Android system is a bit more "open", if you don't count what locking down the particular carrier might do. Apple controls and bans certain apps a bit more often than Google will, and it's easier to get things onto your phone without using the Google Play store altogether. Most Android phones have removable micro SD card memory, and use generic micro USB and micro HDMI connectors, while Apple has no removable chip memory storage, and uses proprietary Apple cables for everything.
Otherwise, both have a pretty robust market of support, you won't go wanting with either.