Well, my first few grows were with bag seed and my first plant yielded over 1.5 oz dry.
As far as quality goes it was noticeably better than the shit it came from but now I want more and better so my latest grow is with some commercial White Widow but I'm a little disappointed in the quality of the seeds I got from Marijuana-Seeds.nl.
Out of 5 seeds all germed but 1 has some kind of genetic defect (shriveled tap root) and another just isn't growing, it germed, popped through the soil, now its just doing nothing.
Anyway, my bag seeds seem to grow well for the most part and produce much better smoke than what it came from but I know there has to be better out there.