Any company that controls its OWN reviews is a SHAM. Obviously they'll trash what's not to their benefit. I've had to go elsewhere to get the REAL picture of them. Fortunately, their web team can't silence (or remove) all reviews like they do on Amazon (with palm grease). Yes, they'll leave complaints about technical issues (apps) and things irrelevant to their bias so they will appear "balanced". Hogwash!
Many on various websites talk about their BIAS when it comes to history and especially politics. HALF of my course reviews are CENSORED as they use the disgusting term "moderated" - and never tell you EXACTLY why they censored it (you have to guess). Such stick-it-in-your-ear arrogance!
SUMMARY: avoid courses on history, politics, religion. Same brainwashing there as in college (you know - "believe me or flunk the course"). Science and exploration is good except where we must endure incessant whining about the new "religion of climate" (you know - vote for me and I'm your savior).