It's true, many aren't super informative. But, they aren't significantly different than the other Adventure books reviews, and people would likely adjust their reviews later if they found the book unplayable. We don't have many other objective data points for reception by the community, but the book does keep selling and people keep tallki g about to run it.
I'll add two things about Amazon reviews;
1. Most complaints about Amazon reviews being inaccurate are valid critiques, but only when you are treating it as a "percentage of quality." If a book gets 4.5 stars, does that make it 90% perfect? Not really, no.
However, where the reviews are useful is comparing books against each other. So Hoard, which has the worst rating (4.3) is considered one of the worst reviews by the community. Sure people gave it 5 stars, maybe for silly reasons like "delivery arrived on time," but those same silly reviews emerge for
all the books, so the only useful way of using Amazon is by comparison.
2. It is incredibly ironic for someone to complain Amazon reviews are arbitrary or not well-balanced data, when it is the only data available. Everything else, like forum posts or even long-form reviews, have no way to standardize and can't provide
any useful data points at all. So although Amazon is flawed, it's the best data points we got.
Sadly, not enough people have left reviews on the combined Tyranny of Dragons to actually know what people think of it's new combined release (17 reviews is a poor sample size). However, one can use the number of reviews left combined with their ratings to estimate ToD popularity.
Hoard has 333 reviews, averaging 4.3. Rise has 182 reviews at 4.6. Combined, that makes their total average 4.4. This puts the combined book in the bottom tier of adventures, most of the drag being Hoard.