To be fair I haven't tried Zen, but Arc still works well. I don't particularly need any new features - so as long as they continue to keep up with timely security patches and Chromium updates I'll probably keep using it. Also - as a developer I would prefer using a Chromium-based browser since it's the most common one used.
I tried Dia a few weeks back and was disappointed in its sidebar and profile features.
schnable|6 months ago