Do not install 5.1.4

5.0.2 paid version works “as expected” (very close to free version though, be sure you need it). 5.4.1 was really a bad experience and should not be advertized as a production version. It simply do not work for mobile viewing.
2 stars because – while finally I got it working as per my needs – I’ve spent hours changing various settings on my site (I thought WP Supercache was the pain point. Spoiler : it’s not) and displayed live crappy page in the meantime.