Ditto the dirtnap. Whoever creates the strain names it. And the people experimenting with genetics are generally the seed banks. It's like Coke and Pepsi. They are brand names and they generally taste pretty close to how they should. But if you drink one straight out of the can, then go grab one from 2 different fast food joints and 2 convenience stores there's always a difference because of how they're mixed as a fountain drink. The ratio of syrup to water.

I've purchased Green House Seed Co's White Rhino. I bought a gram of White Rhino at a dispensary just to do a side by side comparison. Their buds looked and smelled exactly like mine. I'm proud to say that after smoking it, I do believe my dankness is a little stonier.

There are a handful of things that will affect quality. (And by "handful" I mean probably a million, but these are the ones that come to mind.) Genetics - a strain that has been around for a long time is usually pretty stable, so the seeds will tend to pop plants with the same or similar phenotypes. A newer strain may not be so stable, and from a bag of 10 seeds you may get 3 different phenotypes.

Grower skill at growing. Some are better than others. Plants grown under more ideal conditions will have more trichomes and heavier buds than otherwise. Also, the nutrient profile and grow medium will affect the quality and/or taste. Using higher powered HID lights will generally result in denser buds. Using products like Sweet can enhance/modify the flavor. Using products like Gravity can artificially induce denser nugs. Using Purple Maxx may artificially induce more purple coloring leading to product that doesn't look exactly like it's sisters from a different grower.

Grower skill at curing. Improperly cured buds will lose more THC than when it's done right. Especially if a grower is broke, and they use artificial methods to cure the medicine in order to bring it to market quicker. Bastards.

Where I get curious is old school legacy strains. I've seen Lamb's Bread and Matanuska Thunder Fuck at dispensaries. Troll enough forums and you'll come across real old school Alaskan's who will say that those MTF genetics are gone forever (or MVTF if you prefer). Lamb's Bread is a classic Jamaican strain, that people used to say was some of the hardest hitting shit ever smoked. I asked my local dispensary what they thought of the LB they are selling and their response was kinda lukewarm. So, either all of the other strains have gotten better and better over the years, or the stuff they're selling is not the real deal.

I guess the bottom line is that I would expect there to be minor differences in the same product from grower to grower, but nothing huge. As a grower, my only suggestion would be to make sure you provide feedback to your dispensary. The bottom line is that they are the Quality Control department. They should've have sampled it first and determined it's dankness. If they're buying the same strain from multiple growers and they get consistently good feedback on one grower but not the other, they should stop buying the substandard product.

THC tests are $120 here in Denver. I predict that at some point in the future those will become standard. Or all high end dispensaries will either require them from the grower, or submit your sample to the lab and get the report themselves, before buying and selling your product.

I also think there will be a more formal method for associating medicine back to the growers. I can envision a future where every batch of medicine a grower brings in gets a unique ID#. That ID tag goes on the back of the jar with the medicine. Every time a "prescription" is filled the ID # goes on the bottle with the medicine. When someone calls back and says "that Durban Poison I just got was weak ass shit, don't every sell me that again", the dispensary can have a way to keep tabs on it. Maybe it was just one bad batch. Maybe they have an inexperienced grower.