After some serious research we chose PW for all our future projects. Let me just point out a couple of the biggest practical benefits of PW:

1. ProcessWire allows a designer to design any kind of website -- really anything form a simple one-pager to a system of dozens of different layouts -- and a PW developer can quickly setup PW to manage it. The developer will not have to go back to the designer telling that something does not fit the CMS.

2. The final website will look exactly as it was designed. The design can be worked into HTML templates that are simply plugged into PW. There is no templating language (like in EE) and PW will not inject any unwanted markup into your pages.

3. Clients will see exactly what they need to see when managing the site we built for them. They don't need to know anything about technical structures. Say, to add a new publication to a publication collection on their website, they will simply open the admin and click Publications instead of having to know if the publications are in fact "pages" or "posts" in a category called "publications".

Each field can have contextual instructions and advice right next to it and the pages can be structured (tabs, field groups, tables etc.) to best suit the content and editing processes. The end result feels like something that was completely customised.

4. And finally, ProcessWire has native multi-language support that has field-level control of language versions. Easy for the editor, translator and the end user (visitors can switch languages without falling back to the home page). Add a module and it fits right into the multi-language world.

5. Earlier PW lacked tools for managing larger amounts of content. If you had, say, thousands of "publications" and you wanted to filter, sort, order, export or run actions to selected publications, PW did not offer much. However, now PW has a core extension called ListerPro that gives fantastic control for bigger sites. Look into ListerPro that if you have checked out PW for that reason.

Hope this helped somebody.