I really don't like the UI changes its going to make finding a users mod from their profile far harder.
The left column takes up way to much screen retail and the mods tab does not display nearly enough a row of 3, some users have 100's of mods and looking at a users profile to download mods is one of the best ways to get them. I would recommend reducing the amount of space the left column has or move it to the top of the page - it really does not need to be on the left. Then you can have a couple of more columns for mod lists. Another option would be to have the ability to condense the featured mods into a list or smaller items containing image, and title.
Also a there's a visual issue the left column only scrolls down when you get to the bottom of the mods tab - this is unresponsive and therefore an accessibility issue