I have been learning MODx and like it a lot.
It's a great solution to building a site with a CMS that is more of a standard site.

I ported an existing 6-page site to a MODx site in a couple of hours. You put together a template which can be an existing html file for a webpage, replacing some sections with various MODx tags, and load it to MODx, then create pages using that template. My 6-page site looks exactly the same as it did before, but now has an admin section so the site owner can update his own content.

With MODx you can create pages, or just sections of pages, and with permissions give users access to changing just that section of a page. They dont' have to have the ability to edit an entire site to be able to update their content.

MODx has a great menu/links function. You can have any number of menus using the same link organization of the pages and page segments you've created, just using those links you need to show for a particular menu with the MODx tags and code.

I didn't even get into the other features, such as the blog. I took part a little in the forums, very cheery and positive help offered there, though it's clear they don't respond if you're asking one of those questions that have been asked a million times.

I would still use WordPress for sites but MODx is another great alternative.