I use my Sony for straight through, linear reading and sometimes for news/rss feed reading. Also I use it in the subway. Standing and reading an iPad doesn't work for me.
I used to use the Sony exclusively for borrowing library books, but with Bluefire and the Overdrive update coming, probably less so.
I like having the Sony ereader to reduce the wear and tear on the iPad, so I can do more iPad-ish things. Like play Angry Birds.
