I like the fact that I can setup an optimized schedule for when things will post, as well as schedule individual posts for a specific date/time.
I have two separate Buffer accounts--one for personal use, one for business--but you can only be logged into the Chrome Buffer extension with a single account at a time. The solution is obviously to get the paid service to manage more social media channels under a single account, but my work is for a non-profit. It's very inconvenient to have to switch back and forth between accounts on the web. Meanwhile, I can "share" tweets via Buffer from my mobile device, where I'm logged into my personal account.
Buffer has a great Content tab with a full view of the Queue, showing all the posts scheduled to post (for a selected social media channel), and when they're scheduled. You can easily drag and drop posts to re-order them. Buffer will prevent you from scheduling the same post twice--if it's already been shared, you won't be able to share it again, preventing duplication.
I want to share a lot of content to keep people coming back to my social media channels, without having to schedule every single post, and don't want to barrage my followers with a bunch of content all at the same time. I've been able to optimize when my content is posted in order to be seen when the greatest number of my followers are online, helping me to increase my followers, and get more people to attend my events.