Without exaggerating, I've downloaded almost any CMS on Github and Bitbucket and Sourceforge and I'm almost done with testing all of them. I think about 15 remain. With all honesty, I cannot say that I'm impressed with any CMS so far. There is just one thing that stood out, with it's concept, but it's still only Alpha grade quality, that's: http://parsimony.mobi/

I've you're curious what I ended up with, just ping me and I'll share my results, after I've really compared all CMS with each other. Currently I would say that there are about ~10 good quality CMS, with hundreds of miserably coded ones. That is a good benchmark, for how good developers are in the real world, I mean there is only so much space at the top of the iceberg. Not everybody can excel with every project they start (well, except people like Fabrice Bellard)

I've not compared Typo3, Alfresco and other Enterprise CMS, because even when they come with all features loaded, they suck at code complexity and user friendliness

You can't tell me that Wordpress is the only blogging platform that fits to all of your requirements, because there are thousands of CMS out there and you'll spend weeks testing all of them.