Ok, I know it's been over 40 days since anyone posted on this topic, but as a publisher I feel compelled to do so:
After considering the various online formats I chose pdf because it formatted A$$A just how it looked in my publishing software. I've always been frustrated by how HTML can appear in different browsers. By using PDF, I avoid those issues.
In the past few months I have taken readers suggestions to heart regarding the readability of A$$A. I have reduced the font size, and now offer both a 2 column (for the surprising number of readers who print out each issue), and a single column for online readers. In addition, each review is available individually.
Finally, I want to mention once again how thoroughly in awe I am of Jeff's photography and layout skills (coutesy of his better half I believe). There is no better looking publication available.