I grew out both autos and regulars and I have to say I was impressed by the potency of the auto, It was good as the regulars I grew, the difference in potency is rather small. THC is not everything, many regular strains have THC of 15% or below yet get you pretty high. Compounds such as CBD, THCV, CBC etc. also contribute to the overall effect thus the overall cannabionoid profile determines the high.
Autoflowers might appear to give a less of a psychedelic effect because of their elevated CBD content inherited from the ruderalis in the cross, so in that aspect they might not compete.