* The ability to upload an image and resize it (i.e. someone takes a picture with their iPhone, then uploads it directly, and then cannot resize it within Forestry.io to make it sensible for the page).
* Inserting something like a table becomes an exercise in writing HTML or markdown rather than a GUI action.
* We had a requirement to embed some html in which eventbrite provides every time we have a new event (which gives a 'buy ticket' link embedded to the site for our events, but attributes in the html change for every new event we add to the website). You can embed html directly into the forestry.io editor, however it doesn't work when the html is sufficiently complex, so then they need to edit this particular page in GitHub to add the html in. (Note: using pre-built html blocks in forestry.io does not work for this as far as I can see, as the html changes for each new event). I think this happens when a file contains a combination of both markdown and HTML.
* When creating links, you have to find the relative URL path and then type this in, rather than just clicking on another page in a hierarchy as you would in Wordpress. I know this is a tiny thing - but again it makes users find it more difficult to move when they are used to Wordpress.
Despite these things listed, I do think that forestry.io is fantastic and similar CMS programs are the future - It's just that Wordpress has the edge at the moment. I have seen that the team at forestry.io seems to be building a new product at Tina.io and the forestry.io product does not seem to have changed much recently, so maybe this will start to fill some of the shortfalls.
After each save, they thought something was wrong so would end up breaking/conflicting the process of git commits etc as they tried clicking different things because something was taking too long.
This was a couple of years ago so things may have changed by now.