Smartphones are history. Retro is in. Thus, I recommend...
Hey, it was good enough for Christian Bale in American Psycho, so I'm sure it could handle any work-related chores you have.
Seriously, I would give some thought to:
-Any use for "push to talk" features?
-Do you do tons of text messaging, and if so, do you prefer hardware keys, slider keyboard, onscreen keyboard etc.
-Do you really need to be able to watch tons of streaming video for your job, or is it a moot point?
-Are you going to use the phone globally, nationally, regionally, never more than a block from your office etc? That might end up directing you towards certain carriers and certain phones.