Ranked in these QuestionsQuestion Ranking
Pro Very easy to use
Octopress is designed to remove all the time-consuming and frustrating tasks you usually have to deal with when using Jekyll. You don't have to write your own HTML templates or do any configuration to get started. The default template also takes care of any basic CSS/JS you need to write to get going.
Pro Lots of plugins (from Jekyll + 3rd party)
Another advantage of being based on Jekyll is default access to the extensive plugin system for Jekyll. There are also plugins developed specifically for Octopress.
Pro Based on Jekyll
As Octopress is simply a framework on top of Jekyll, it benefits from being based on one of the most popular site generators available. The primary benefit is that it is backed by git and is built in such a way that the site can be easily re-generated if the content changes.
Pro Uses Markdown for writing
Uses the Markdown syntax for writing blogs.
Adding a new post, for example, causes the entire blog to be regenerated.