Pros: I like the way it incorporates with other things via Powerups. I use Trello Butler all the time (both the bot and the powerup) to automate just about everything I do on Trello (love those dashcards especially!). I integrate it with Zapier to parse leads on my Trello board and keep track of what happens on Google Sheets.
Cons: Will take time for new users to understand and start using the tool. - moving from card to card to check and the update is little time-consuming.
Overall Experience: Very easy to share boards with anyone to have a view of the lists and allow permissions to comment. Overall the free version is a very cost-effective project management tool- because its FREE!!