If you like FL's interface and workflow a lot you will probably have trouble getting to grips with other software (especially Reason!).
If you're not planning on recording anything then you can get the "fruityloops" edition of FL which doesn't have the advanced routing and recording capabilities of the producer edition but is half the cost and still lets you use VSTs and all that jazz. Then if you ever need to upgrade you can pay the difference later, or if you want to start using a more recording-centric DAW like ProTools or Cubase you can run the fruityloops edition inside other DAWs as a ReWire client.
btw: been using FL for all of my WB stuff so far. It's pretty great!
However, I've done my research, and that version has no automation clips! No fades, etc...