man i just grew 8 nirvana short riders this summer, it was my first grow and was very easy. The high is awesome, not too overpowering and a bit energetic, they taste awesome too.
Check my grow journal from my signature, i also have a smoke report there so that should tell you all you need to know!
Happy Growing! just to add: nirvanas autos DO autoflower, but the autoflowering starts when the plant is big enough ( has enough leaf nodes to carry the buds etc.) so it may not be precisely at x amount of weeks but when the plant is mature to flower, in my case it took in average 6 weeks ( i grew outdoors so that explains the longer time before autoflowering)