I buy autoflower seeds from the i luv guy. Excellent seeds, and presumably F1.
I've cloned them by turning part of the plant (S1), I've crossed them with another of themselves (F2), and I've crossbred them (F?). 7 autoflower varieties they sell.
Only the cross bred ones have significant variation in genetics (never cross with blueberry if you expect autoflower).
The S1 and F2 seeds I've made are every bit as strong and potent as the parents. And if there's genetic variation, it's not significant compared to the growing conditions.
The seeds from i luv tend to sprout much faster. 1.5 to 3 days. But perhaps they know a trick, like microscoring the outside to speed up hydration.
Their seeds have a 100% germination rate in my experience. But this could be because they examine them with special tools to look inside. I usually pick the poorest looking seeds from my batch, so as to use those up first.
So mine have a 60% average germination rate, sometimes as low as 20%. On the other hand, I can make 1000 seeds on a single plant, so the germination rate loss isn't even significant. It's more of a problem that California state limits us to 6 at a time.
The MAIN difference I've found is the THC content percent rating. If it's 18% or more, you get nice dense buds covered in sugar. People who use medical marijuana always say it's good.
If the percent is 14% (like low ryder), people complain about the buds and they don't look dense even with the best possible trimming.
Amnesia Haze is my current favorite. Very dense with trichomes, nice smell. Poor yield but it matures fast.