r/miata - Useless for the entire subgroup that takes their car to the track, and will very likely still give advice, it'll just be bad or outright dangerous.
r/cigars - Totally jump on bandwagons, and generally are "new" to the world of cigars.
To highlight another point, a lot of more niche subs largely cater to those new to the niche. Those are the same people commenting and giving others advice, whether they really have the knowledge to or not. This mechanism over a few months seems to turn everything into an echo chamber, and you end up with new people jumping onto a bandwagon without enough info.
Same goes for Amazon reviews, to a large degree - That $50 set of sockets might be great for someone who wants to change their oil filter, but will literally shatter for someone doing more involved work.
I think this is where the traditional forums are much better. I want my info from "serious" people who hang around the community for years, not from someone who came into it a few weeks ago, and really just want some upvotes/points/whatever.
I find it easier to sort out on a subreddit who's an experienced, knowledgeable person, who's inexperienced, and who's a shill. I can sort that out on Amazon reviews, but I have to do that on my own each time. In a good subreddit, the community is doing that, both participants and moderators. You do have to keep an eye out for poorly-moderated or overly-shilled subs.
If you buy a Husqvarna 372 or a Stihl 441, you'll probably never need to buy another saw in your lifetime. I prefer the Husky 372 (and older models like the 262 and 288), because it has a separate on/off switch and choke, whereas most saws have a one-piece switch/choke, with an off, on, and choke position - if it's cold and I've got gloves on, it's too easy to flip the lever down too far when starting, and shut Stihls and the cheaper Huskies off.
https://www.reddit.com/r/BudgetAudiophile/comments/dq5d9c/i_...
I have been lurking on r/chainsaw, r/budgetaudiophile, and others for a while. I was quite comfortable buying a $400 chainsaw, knowing what I was getting that I wouldn't find in a $200 saw, and what I didn't need in a $600 saw. The same goes for the $130 pair of speakers I just bought. I had no idea what to get from looking at Amazon, but a little time reading r/budgetaudiophile led me to an affordable pair of speakers that gave me the best listening experience I've had in decades.