the most potent pot ive smoked has been bush and they grow it all yr round, several cycles a yr, even thru winter, depends on where u live and how much yard space u have and how much u are prepared to pay for the electricity i guess.
The other problem with indoors is that it can lead to a fire in extreme cases, thats an added doh.
oh and the penalties for getting caught are worse as well. double doh.
oh and alot of the places that sell the lights and other things that go into indoor grow set ups are much more tightly monitored and kept track of these days. triple doh.