Zen Mojo - REST vs native transport?

I am going to start playing with Zen Mojo (again) and as I understand it there are two ways to manage moving data to/from your Zen Mojo page:

• interacting with REST services
• using Mojo's built-in transport

I would like to understand the pros and cons of each approach.  Which is recommended in different situations and why?  I would like to create a sample application that will hopefully be reusable and helpful to others and I would like to  understand which approach to pick for my app. 

In the experience of the Community, how do the above two approach compare in terms of:

1. Ease of use
2. Rapid application development (which is faster for getting a workable app up and running?)
3. Maintenance time / costs
4. Flexibility

I would appreciate hearing people's experiences and recommendations.

Thanks!

Ben