Outdoor is the shit, no power bill for the sun and rainwater doesn't leave burns or deficiencies. You'll be able to completely control indoor growing, they're can be bigger yields depending on training, nutrients, etc. Outdoor also can only be done one time during the year, starting april and seasons end about february when light switches back to 18/6 or 16/8 light time for vegging. I particularly like outdoors because cold temperature help plants res up, they'll get purple hairs and look insane, mines turning pink and purple and it's about 5 weeks into flower. The only downside I see could be insects or pests, they can easily be avoided though.