I like to grow different breeder, since i am growing i tried a lot. I am an European grower so i like to try different thing. Over the years i grew american, dutch and spanish genetics...
The most dense bud i ever saw is BY FAR the Hash Fruit from cannabiogen. It's Sandstorm x Peyote Purple. And Sandstorm is the Pakistan Chitral Kush cross with a fat Moroccan indica. I grew both the Pakistan and Peyote in other cross, and in term of density and production it's low or very low for both...
However the Moroccan gene make all the difference in the Hash Fruit cross. When you get a peyote or pakistan pheno it's low yield but most pheno were Moroccan dominant, i think the sandstorm female they use is very Moroccan dominant. A friend of mine did the grow under old and not very powerfull led light, it was it's first time and of course he fuck up the feeding (lightly) but even then the Moroccan pheno produced enormous bud...
But the most funny part : just take a small piece of bud, grind it, and you get a mountain out of the grinder. Back then i never saw that...
Funny thing, you should have seen the difference between these indica pheno and the only peyote pheno. 2-3x time more vigor and stretch for the moroccan pheno, maybe 10x time the yield or something... But the peyote pheno smells very hard of passion fruit and was very frosty. Incredible purple color also, but forget the vigor and production. I still have some photo of it in my IG.
So i say it loudly, density was really out of this world on these. And the smoke by itself wasn't bad. Taste was classical afghan indica, hashy with influence from the pakistan, not a lot of terp but it was ok and it smoke fine. High was also very decent, very stoney and far from being weak.
I mean i really like american genetics, but even if you get rock hard bud from your strain you need to keep this in mind : Kush suck in production and you guys just crossed everything with Kush, then hardly inbred the result. With american genetics you can get good production and density... for a kush, which will always be medium at best compare to truly productive and dense variety. Of course it won't be the same high or terpene.
It's a long time that i think i will make myself a proper selection of these hashfruit or sandstorm, and try to cross one of these ultra dense pheno with all my collection of tasty american genetics. Sure i will get some surprise in the offspring.