I like that I can track all my blog posts and social campaigns in one place. All scheduling, social sharing, and even social metrics, all in one place. The Chrome browser extension is also quite helpful for me for the times when I need to curate content instead of just publishing my company's own content.
I absolutely LOVE the integration with the headline analyzer. It's really great to test out different variations of a headline as I'm building the piece of content.
I dislike that I don't have the time I need to dig into using CoSchedule to its fullest extent. I know the software can do a lot more than I'm currently using. :)
The other piece that's not my favorite is the interface, which has recently gone through an overhaul and is now much better than it used to be. The social and image helpers are really awesome, but do get cumbersome (from scrolling) for when I have many different text and image helpers set up in the same social campaign.
The only other piece that I dislike is not being able to insert a text helper at the cursor point of my entry. It will only show up at the end of my post.
CoSchedule acts as my editorial calendar as well as my social sharing solution. It helps keep me organized and on track with managing a multi-category blog as well as the social sharing for each post.