So let me get this right. We have:
Two people who own both a Kindle & a Sony reader who say they found managing collections on the Kindle easier than the Sony.
One person who doesn't own a Kindle and who seems only to post negatively about Kindles saying the Sony is very easy and the Kindle Touch not so.
Thanks JSWolf, I was under the impression the Sony was easy to manage collections on, now I know that it's probably easier on a Kindle.