Honestly fake reviews are to the point where naturally I’ll just google “$product_name Reddit” and get some more honest reviews than anything I find on Amazon. Yes there will be astroturfing, but you can also get into some more niche communities with more real feedback and discussion.
Similarly, my policy has basically become "find the relevant little subreddit or niche forum for $category" and then read/ask on that. Has worked out pretty well so far.
Especially if it's a product category that gets daily use from the people who purchase whatever it is, it seems like there's usually some passionate people around who know what they're talking about. Only issue is that you can get deep into the weeds on personal preference stuff.
I recently did this looking for an under-sink water filter. It’s usually useful, but in this case the recommended products were from a Reddit post from 2.5 years ago. More recent Amazon reviews indicated this was a good product initially, then the quality declined over time.
That’s another tricky thing to fix: products have the same page and information, but the product does change over time. And that’s hard to indicate in a review because the changes are so subtle.
Depends on the subreddit. Most of them are, as you say, filled with kids. The problem with that is if you ask for a product recommendation, they interpret that as "what's the cheapest X", which gets pretty annoying depending on what you're trying to buy. However, reddit in my experience is great with niche things with smaller subreddits, like /r/hometheater and /r/fatfire .