One thing in the Things vs. OmniFocus debate: sync speed. Things syncs far faster than OmniFocus does. That said I've also found OmniFocus to be far more accurate in syncing. Things is terrible with proper syncs when a given device hasn't logged in and synced for a bit. I always get old and/or duplicated items. This does not happen in OmniFocus.
On why we should be writing
I go through a crisis of purpose in maintaining this blog often, very often. The usual litany of questions I think many like me ask: why am I doing this? Will anyone read it? Am I doing it well? Etc. I ran across this great but of wisdom from Akindele