Re Twitter: I dig its portablility and the fact that you can focus on the CORE of the post. Also, its easier to find resources specially if you're running a stripped down/authority only feed like
http://twitter.com/#!/askmr5dollar I've also stopped trying to get gobs of followers using hummingbird. My focus now is more on content weight.
Re blogging: Its nice to cross reference posts and the length flexibility helps a lot.
Each has its place but which do you prefer?