It's still possible to get somewhat of an accurate understanding of what you're buying if you read some reviews.

I read ~10 two star reviews, ~10 four star reviews, much more depending on price. One stars tend to be full of stuff like "product hasn't arrived", "garboage", user errors. Five stars are plagued by spam and paid reviews, and also a lack of details. Three stars seem to be split between very picky buyers (esp. hate the "I paid $3.50 for this and it's not the omega particle!") and people afraid to leave lower ratings for reasons.