6 reviews is nothing. More reviews the merrier.
When we buy stuff we often use an independent consumer site.
RPGs are a lot harder. Ive used ENworld to filter my purchases. Here's what I haven't bought.
Dragonheist
Dungeon of the Mad Mage
Storm Kings Thunder
Acquisitions Incorporated
Shattered Obelisk
The Vecna One.
Strixhaven
Dragonlance
Planescape
Spelljammer
Stanger Things boxed sets X2.
Descent into Avernus
IMO this is mostly a quite solid "do not buy" list, but I would argue in favor of a few on there.
Dragonheist - very terrible, yes
Dungeon of the Mad Mage - I think this is well worth buying, but not to run the whole as a campaign. Most of the dungeon levels are very, very good and can be cannibalized. Most groups just don't need to run 23 dungeon levels. Kind of a brilliant book, though. Third parties have done color versions of the maps which really elevates the experience, especially for VTT play.
Storm Kings Thunder - really bad
Acquisitions Incorporated - the adventure is quite good, but definitely not for all tastes. By no means a bad book.
Shattered Obelisk - hugely disappointing
The Vecna One - The behavior and plan of the central villain is nonsense, which hurts it a lot and makes it hard to salvage. Has some good set pieces though.
Strixhaven - Bad
Dragonlance - This is pretty good tbh
Planescape - the adventure is one of the worst official WotC adventures of the 5E era. The setting book and bestiary are good though.
Spelljammer - I actually really like the much-maligned Light of Xaryxis adventure. Setting book is disappointing, bestiary is ok. Kind of the mirror image of the Planescape box.
Stanger Things boxed sets X2. - The first one is a gimmick, but not terrible or anything. The boxed set from last year is GREAT and anyone skipping it is missing out on 4 very solid tier one adventures and excellent production values.
Descent into Avernus - pretty bad as written, yeah