Three Recommended Technologies for Digital Student Portfolios

Right now I am closing in on finishing Chapter 4 of my upcoming ASCD book Digital Student Portfolios: A Guide for Powerful Formative Assessment (working title).

The first three chapters offer a definition of digital portfolios and why they should be utilized in every school. Now I am at the fun part: Describing the technologies that can be used for this type of initiative.

Next is a graphic I have "rendered" that summarizes the pros and cons of each of the three recommended technologies for digital portfolios: blogs, dedicated portfolio applications, and websites. It's a draft. What are your thoughts on this topic? What am I missing or possibly misinformed in my knowledge about these tools? Please share in the comments.