I smoked just about every kind of weed there is and the strongest smoke by far was from an autoflower called white dwarf. If you had smoke from both let me know what you think.
My only experience is Northern Lights auto that I grew, and it was a nice buzz for me. The only time I tried NL from a dispensary I didn't much like it. People will say that autoflower is always less potent, but I guess it depends on exactly which batch you sample.