The ones that you mentioned there, as the old products that used to sell well, they at least for the most part met label claims - with the exception of Craze, which was pretty well documented.
Many of the ones that you're referring to that are only sold on obscure sites and the reasons for that is that they want to fly under the radar and they know that getting sold on mainstream sites would draw too much of the wrong type of attention to them.
Plus, many larger retailers require things that those wouldn't have - like being FDA registered, cGMP compliant, liability insurance, etc.
In regards to you saying that they appear to meet label claims, I think that most people would agree that many of the ones of that type don't - and that a lot of their customer bases hope they don't because they fall into what I mentioned in my post above as category #3 of customers:
3) There are people that take things intentionally hoping for or wanting them to be spiked with amphetamines or amphetamine like drugs.
As for what general people in the gym use, that's always going to be the most heavily advertised brands - that's regardless of quality, results, etc. bc the average consumer buys based off of advertising.