I know that i pulled my 1st plant at 6 weeks. The things i lost were taste, smell, and the most important yeild. I think your better off waiting 8-10 weeks for flower. But some strains like Top 44 can be harvested in 6 weeks.
allways go by the trichs when harvesting , i completely ignore any flowering times given by the seed banks as they are usualy wrong ,the trichs are the only thing to acurately tell you when shes ready .