The quality of smoke is generally determined by genetics however when it's picked and how it's cared for are factors as well but no matter how well it's cared for and even if it's picked at exactly the right time the genetics will determine the THC content. I'm not sure a mid-grade plant looks any different then any other plant. A clone will be a carbon copy dna match of the mother plant, a seed will carry the dna of both mother and father so there is an unknown variable but in general the seed will produce similar buds to what it came out of but it could be better or it could be worse. I've seen killer green bud grown from seed INDOORS that produced no high! I smoked half an 8th to my head and kept wondering when it would kick in.