One of my favorite things about the extension is how smoothly it integrates with other things. It seems there is already a plugin to integrate it with most things that are related to it (different comment systems, jomsocial, etc).
However, the absolute best thing about this extension is the support. If you're anything like me you know how frustrating it can be to have a question about an extension that you just can't get figured out, and watch your question sit idle on the barren support forums for weeks. I have submitted quite a few questions about easyblog using both their support forum and email ticketing system, and everything has been responded to and resolved ridiculously quickly. I mean, one time, it took overnight to get a response and they actually apologized to me for the wait. That was still a faster response than any other support request I've submitted for an extension.
The best part is that none of these support requests were about a problem with the software itself. Rather, they had to do with customization (which they say they don't technically support, but they're still willing to go the extra mile to help you with it even offering to log in to your admin site and make the change for you at times) or settings that I somehow missed.
If you need a blog component for your site, I can't imagine you'll find anything better.