Thank you a lot for answer on my critics. My point was help you make your resource better, in the first place.
Now some things I see not quite professional implementation of the site (well, at least for my cultural background).
First, if I click on PDF download link, I expect that I'll either will see a file or a clear request to login. Now it is just an empty page, which looks as if the file is missing or the site is misconfigured. In most cases, your visitors will just go away.
Then, if one login to the site, the visitor is redirected to main page, and it is not easy to return to necessary page. Even then, it is necessary to reload page or place some other button to actually see version for registered users. I treat this as bug.
Finally, normally PDFs are for either printing - your is not optimized for this or for seeing as presentation. To understand that this cheatsheet actually has a text layer is far from evident. I'd recommend to reformat this for PDF.
And one more recommendation: code snippets are much better if syntax highlighting is on