I've only been commuting for a 2-3 months now so I am very entry level as well. I'm currently using cyclemeter on a mount on my bike. Love how customizable it is in terms of what can be displayed on the screen.

In terms of phone vs dedicated unit, I chose the phone because of:

- Price: The basic version of the app is free and I wasn't sure how much of a dedicated bike commuter I was going to be. Also, since the phone's display is larger I am fairly certain I can display more information at once.
- Battery Life: You would think this would be a con judging by what most say but I think this highly depends on how long of a commute you have and what kind of phone. If I were you I would do some testing. I have an iPhone 6+ on a 25 minute trip one way (50 minutes a day). At the end of the day I still have > 40%. Since I charge my phone every night anyways its actually an advantage to use my phone since I don't have to worry about charging two devices.