I know I am not the first guy to say this, and I definitely won't be the last. But having just written my first addon for XF, I can't believe how ridiculously easy it is to make addons for XF and how great the MVC architecture is. Once I figured out the basics which took me a day, I could write the entire addon in an hour! I can now fully understand what Kier meant when he said people will be surprised how quickly we can develop new features. That's because since the basic functions and classes are properly done, it's just a matter of using your imagination to extend whatever you like. Cool software!