Gives your site great speed boost. My site scores 25% more points on GTMetrix if JHC Optimize is enabled.
Samuel offers top notch support, he answered every ticked within a couple of hours.
I suggest PRO version, it has more features.
It has many great features (for example you can use it as a static box or a slider).
I especially liked the option of choosing colors - other similar modules just have blue Facebook color and nothing more...
Support is excellent - Piotr answered me within hours (even during weekend!).
...and its free, so there's nothing more to ask really :)