I think the best way to sum up this entire argument sould to just always assume any seed that you buy with a popular name or name you have heard before is to automatically assume S1.
Well, I don't think you need to go that far.
Lots of lines ARE what they purport to be. For example, while there were times when ceeds for Herijuana weren't commercially available, and the line was borderline "clone only", right now there are probably three or four sellers on the market now with Herijuana ceeds. These aren't S1s, they're legitimately bred ceeds from male and female inbred parents. And this is true of any number of other inbred lines that are well known by name.
The problem is specifically with popular "clone only" lines (eg Girl Scout Cookies, Blue Dream, EC Sour Diesel). In cases like that, any version from ceed is likely to be different from the clone only line.
How different? It depends on the line, and possibly luck of the draw.
Does it matter? Depends what you are after.
With something like that, you should do your homework before buying it. Find out what the original genetics are, how they were sourced, and how the ceeds in the pack trace back to them.
Just because something is an S1, doesn't necessarily mean its "crap"; it depends on the exact line and what your expectations are. Most of these will put out
some good phenos, though they won't necessarily be identical to the parents, and you may have to go through a number of plants to find the good ones.
For example, I had good results growing out Sickmeds S1 version of Green Crack from ceed, but I also came into it with fairly limited expectations. I knew this wasn't going to be the same as the "clone only" line and wasn't expecting that. Meanwhile, the breeder outright told me I should expect to see different phenos, but added that in his experience virtually all of them have similar fast flowering times and flavor as the original clone only line. So the breeder wasn't trying to conceal anything here and I think set the bar appropriately for what I could expect.
I ended up exactly with what was described, and I was satisfied with the result (which, if you're curious about, you can see in my grow report, linked below). Since then I've heard of some growers getting individual phenos basically indistinguishable from the original "clone only" line, some worse, and at least one describing a pheno he said was BETTER than the original. My takeaway from having grown this is that at the asking price (which is $80 for a 10-pack of Fem ceeds) this is a reasonable consideration for someone who wants to try the original but can't source the clone.
I totally this should be the responsibility of the seller of the product but lets face it, this market isnt regulated like a normal propriety.
This comes down to whether or not the seller has integrity.
This is why, by the way, I don't do business with BS artists. Even if their genetics are great (which sometimes they are. . .pollen chuck enough elite clone only strains, and eventually you will end up with something good), I don't like to reinforce poor ethical business practice with my dollars. And I don't need to. . .there are plenty of excellent lines out there by breeders with integrity, including young "up and coming" breeders who can use the support, and I'd rather direct my money at them to help keep them in the marketplace at the expense of the BS artists.