I promised to report back on my experience of using Trello after a month. Here's the good and the bad:

The good

• Immensely satisfying to fill it in in the first instance. I spent a happy hour or so populating Trello's board with different streams of projects. 
• The colour coding is a really nice touch (you can assign colours to your own choice of labels, i.e 'video', or 'advertising'). 
• You get one free 'power-up' to make your Trello board integrate with another element. I used mine to be able to view the projects in calendar form which made things easier to visualize.
• Free, which is great when testing the waters. 

The bad

• I wish the calendar was a Google calendar so I wouldn't have to log into Trello separately to check tasks. I didn't seem to get (noticeable) notifications in my inbox for tasks past their due date either - so not the most practical when you're on the move.
• I wish more 'power-ups' were part of the standard package, i.e card repeaters. It's unnecessarily clunky to keep recreating whole projects. 
• It's not very satisfying once you've completed an activity - you get to 'archive it'. The list-lover that I am would have liked a box to tick, or some gamification element to the process. 

The Ugly

• This, ultimately, isn't Trello's fault, but my colleagues did not take to it beyond an initial logging in. This made Trello of limited use as the advantage should have been in collaborative planning.

So, unfortunately, I am going to phase out of Trello. On the positive side, it's taught me what elements to look for and appreciate.

Our team's internal communications system will be moving to Slack soon. Once that's completed, I will trial Flow next, which integrates with Slack.