I reckon if you're in an apartment or don't have much garden space, hydro growing is the better option to me. Hydro is much cleaner cos there isn't really any "dirt" to deal with. A blessing when your grow room has a carpet and you're anal about cleanliness...
As skolley says you need the outside space element to be able to get the best out of an organic grow, unless you're getting your soil premixed like from Jamies GS. You need the space to mix soils, do composting whether its worm farming or a compost heap and a place for your soil to cook.
Hydro growing can be expensive but it doesn't necessarily have to be. At hortishop you can get those powdered nute packs for 60 bucks which aren't as good as Nutriplex but they aren't bad either. At the end of the day both methods are way cheaper than buying bud