Great plugin after you cope with all its problems

It is a great plugin, I am using it on my site. With its help, my posts are having 100 PageSpeed grade almost always and are served very quickly, usually less than 0.2 sec for the initial html and about 0.5 sec the entire page.
Thanks, Frederic Townes!

Nevertheless, I give it only two stars, for many serious problems it has:

1. It is quite complicated to configure and very short on documentation. For this reason many people have written their versions of configuration directions. As all published directions did not work for me, I have written mine:
[Link redacted]
Nevertheless, the plugin author who knows how it really works, would have been able to explain better.

2. Minify feature uses <link> to embed css, with plugin FAQ claiming that it is non-blocking while Google PageSpeed considers it blocking. For more details see [Link redacted] Get PageSpeed 100, Part 2.

3. Minify Auto mode does not embed external Javascript in a non-blocking way; see more details in [Link redacted]. I have submitted a bug for this on January 27, 2015.

Due to items 2 and 3, I am not using Minify feature of this plugin and using another plugin, Autoptimize, instead.

4. Cache preload is an important feature but I have not been able to make it working. In my experience, when it is enabled, it just removes cache but does not replace it with a new one. I ended up disabling it and replacing it with a cron job as I explain in [Link redacted].

5. The annoying popup that many people are complaining. (For the directions how to tame it, see [Link redacted].

IMHO each of these five major problems deserves one star off. However, I appreciate this plugin and I cannot give it the minimum of one star; thus, I give it two.