I really like the never ending list of tools that is available to me! The weekly reports give insights on what is working and what is ultimately a waste of my time. Most of all, I like the keywords/tags analyzer and how much it helped to get my products that had little to no exposure seen.
I like how easy Seller Tools has been to schedule. It has helped me quickly get things out to social media without much thought. I like that you can choose how far apart you want your posts as well.