i've grown both. i had the f2 version of k.o. and it will literally knock you out and i blow and have been blowing with the best for 16yrs. super frosty with a earthy skunk coffee pine thing going on in flower. finished fast, not much stretch, not branchy at all. single cola type plant. taste leaned more toward the earthy side. at the time sannie was giving away mixed kush freebies with some of the same genetics as k.o., and i remember liking a sweet almost fruity pheno of the mixed kush better than the k.o., but, my associates went nuts over k.o. and the potency. give her an extended veg and you'll have great yields(in my opinion) of top of the line narcotic DANK!
just finished up my first run of extrema in august. what a broad! had cheeseberry and chocolate rain going at the same time and extrema reminded me of the middle child always trying to out do the other siblings, she out frosted them both. all phenos where uniform chemdog dominate skunk all the way, moderate stretch, phat dense buds, big yielder with strong branches. she's a nute whore. the cheeseberries finished quick like the k.o. and i think i took the extremas a week later. i remember them being extra ripe so, around day 60-63 they'll be extra crispy. trich production was bananas! expect crazy trichs very early on. i remember starting them on purple max at the beginning of flower and by week for 4 the buds looked completely white even the lower ones. plants had a beautiful structure, one of the frostiest strains i've ever seen. my associates really went for this one.
i was sampling a quick dried branch(no cure) in my friends car and had a brown paper bag full of buds to show her how frosty she(extrema) was and fucked around and left the bag in her car. when i got home it hit me(3hrs) later. i called her but, already knew i wouldn't see that herb again. needless to say she said, she'd cleaned out her car and threw the bag away, lol. it's funny because, she sales super exotic and all she could say is that shit is so, LOUD i know we're going to jail riding with it. anyway, i loved both strains and recommend them both, it's like choosing between kids.....cop both