Im using Fl6 but have used reason and abelton live
personally I know the ins and outs of flstudio since i started with that program and it obviously supports VST instruments so with the abbility of VST instruments like sampletank , absynth, kompact, intakt, ect... makes this program off the wall. The actual interface of this program is absolutly incredible to make any kind of music expecially with some of the vst instruments i have mentioned!!!
BUT... flstudio also sucks balls... I love my midi controllers and practly nothing supports flstudio as in the end you have to be some kind of wizard to make a dashboard interface for your midi controller!!@! either that or hope that someone has done thatalready and you can download a premade dashboard... (this was a bitch setting up my BCR2000)