I've not dug into the 5.6 version of the blog component yet, but I have quite a bit of experience with the pre-5.6 version. To be honest, it's a feature that I've had some struggles with extending or customizing, but they seem to be making improvements version to version. For this reason, I would recommend using whatever is most recent.
Make sure to ensure that your licensing supports use of this component, though. Sometimes that can get a little tricky.