Outdoor bud gets a lot higher amounts of uva & uvb light. Now I know from experience that a UVB bulb in an INDOOR grow will significantly improve the amount of capitate thrichomes produced by the plant. With the sun kicking out UVB and every other wavelength of light, a lot stronger than any HID light then it stands to reason that outdoor bud should certainly be stronger then indoor. That being said, due to other environmental factors (heat, wind, drought, wildlife etc) indoor bud grown in a perfect climate will always out preform outdoor bud in terms of quality.
Now when it comes to effects, the Buddhists believe that as a cannabis plant grows, it takes its surroundings in and this can change the effects of the buds. In theory - plants grown indoors (like battery hens) will grow nice buds but the outdoor bud will be happier due to it being sat in the sun all day with the wind blowing through its hair and it's roots being able to stretch as far as they want. This will effect the high according to Buddhist philosophy.
Harvest time can also be a cause for different effects. You can have an indoor plant harvested when its thrichomes are milky and the exact same plant grown outdoor and harvested with amber thrichomes and both plants, although genetically identical, will give different effects.