Lack of interest and support

Only install this if you want to see what the paid version of the plugin can do. This free version has an unsolved bug that prevents Google from indexing your AMP Woocommerce pages, making this version useless.
I came to know about this plugin when I installed AMP for WP from the same company. In both of them I’ve seen a developer lack of interest in solving bugs in the free version of the plugin. Not small bugs, but crippling bugs that render the plugin unusable, debugging it, I saw it was very simple to fix; just a missing meta tag.
I don’t know the devs reasons for not solving bugs in the free version but whatever their monetization strategy is I wouldn’t trust my money to a company that give such a support.
This review may change if they change their strategy but even then, needing negative reviews to start to show interest in their own plugin is not a good sign.