advantage of using Elastic MapReduce over Standalone EC2 cluster?

[Walrus theCat]

Hi y'all,

I'm reading this article (http://aws.amazon.com/articles/4926593393724923)
and was wondering why I'd want to use EMR over just the standalone cluster
you can launch with the .start-ec2.sh script?

Cheers,

WalrusTheCat