My issue with Light was it gave the users too much control. I personally want to lock a site down so that its editors would only be able to update a few things:
Light offered the ability to add blogs, calendars etc. I couldn't turn this feature offering off. I trust users to make small changes, but when they have the ability to add pages, and add new features, they will quickly degrade the user experience because they don't know when these features are appropriate.
I'm currently evaluating Contribute, but all of my XHTML compliant pages break in edit mode.
If anyone has a good solution for me, I'll be eternally grateful.
~jeff