Retina MacBook's Core M CPU is vastly underrated. It is generally capable of running all basic computer stuff (clerical/office work, web browsing, media consumption) with ease. It can turboclock and is not incompetent at things like rendering footage in iMovie or even Final Cut. With the SSD and 8 GB RAM it is generally capable of running most production software, though it may need more time to process footage or audio once you have completed your work on it. It's probably not the machine you want if you are a serious power user for these types of apps but if you're tossing footage of the kids together for grandma, it works great.
Make a list of the apps you need to have and check into how they run on the Core M. You might be surprised by how effective a machine it is.
That said, I do think the 13'' MacBook Pro is a better value. You're giving up weight to be sure but the 13'' Pro is not a particularly heavy machine and is more then capable when put side by side with a similar desktop.