There are several reasons mine got as large as it did.
1. 3 Gallon pot. I've seen many small S.R.'s in 1-2 gallon pots
2. Nothing done to stunt growth - never topped, supercropped, Fim, LST, or anything similar. Just planted and watered and fed.
3. Proper attention to the Root Zone: Healthy Root = Bigger Fruit
(a) When mixing my soil, I added a generous amount of Pearlite
(b) Also while mixing up soil - she got loads of MycoMadness - beneficial bacteria
(c) Lastly - she got Humboldt Roots, root innoculant mixed up in the soil
(d) Properly fed & watered
4. Nutrients added at appropriate time and in correct levels.
(a) Fox Farm Big Bloom & Grow Big during "veg" + Humboldt Roots + Cal/Mag+
(b) Big Bloom & Tiger Bloom during flower + ChaChing + Gravity Flower Hardener + Cal/Mag
(c) Feed, water, feed, water. RECENTLY I have been going with feed, feed, water, feed, feed, water
(d) PH of water & Nutrient solution has been at 6.3 nearly EVERY time.
(e) PPM has been at appropriate levels for plants age/needs
5. Lighting, temperature, & Humidity
(1) 250 watt HPS thru entire grow for 2 plants = 125 watts each in small closet
(2) Temps stay between 68-75 except for extremely hot days like today (heat index was 105). Closet temp never exceeds 78f
(3) Veg RH was 55-60%, Bloom is between 45-53%
I dislike Nirvana for my own reasons, but more from a customer service standpoint then any stability concerns. I wonder if you are bashing them based on personal experience, or "legend"? I haven't been in this game for a great deal of time, but the way I understand it is that Nirvana USED to have a bad reputation, and unstable genetics. BUT that was the case with nearly ANYONE progressive enough to start marketing the "new" AutoFlower strains. Since then, they have come a LONG way. I have to say, the shipping was discreet and FAST, and I got what I ordered. The 2 Short Riders are nearly identical, only one of them is about 8" shorter since she's been a bit neglected and pushed away from the light. BUT as far as plant & bud structure, they are identical. Neither one have hermied. Neither one had any problems auto-flowering under 18hrs of light. Neither one seems overly succeptible to disease. I also ordered some Bubblelicious seeds - a friend is growing them, and had 3/3 germinate, 3/3 female, 3/3 autoflower, all 3 were the same pheno. I ordered some Northern Lights and gave the seeds to another buddy - no complaints from him either. Look - these Auto strains are meant for a certain niche of grower. They definitely have made a place for themselves. I'm probably not going to grow them anymore, but not because they are unstable or shitty, but because I can't clone the one I end up falling in love with.
Sorry if you actually DO have a legitimate concern about the stability of Nirvana's seeds, but I'm getting SICK AND FUCKING tired of all the people telling me I got fucked by them. NO I DIDN'T. I know what I ordered. I know what I got. My only issue with ordering from them was that an order I cancelled immediately was still charged to my account. It took several weeks to get straightened out. I ended up just taking more seeds then I wanted in order to resolve the matter, but I would have been MUCH happier with my MONEY back.