I think the 350 grams/m2 is just a unit of measure to base other strains off of. So a higher yielding strain might be rated at 400 grams/m2. In all reality, the breeders don't know where you'll use these seeds (indoor or outdoor) or what your experience level is. In regards to big yielding strains, just go to any reputable breeder and look at that grams/m2 measure. I like serious seeds, soma, THseeds, White Label etc. All of them can be found at seedboutique.com.