What do you like best?
The strongest suit for Squiz Matrix was the clear and simple user interface it provided, that gives confidence to non-expert users, while never seeming at all underpowered or limited in functionality. It does what so many other systems try and fail to do - do the complicated stuff for the technical people, while enabling simple stress-free editing for the basic user.
What do you dislike?
Nothing different to any other CMS - it can be slow to process at times, when there are a large number of people using it at the same time.
Recommendations to others considering the product
If you are looking for a tool that everyone in your organisation can engage with without fear, this is as good as it gets. As easy as Wordpress, and as powerful as Drupal. It's a real world solution with great support and extensibility.
What business problems are you solving with the product? What benefits have you realized?
There were two core problems - a requirement for devolved content management, while enabling strong cross selling and systems integration. It successfully enabled both very well.