I'm not an active Reason user, but I will add this much.. its a fantastic way to learn the concepts of synthesis and sound routing, sound design, etc. Its the most graphically oriented music production app available. I know a lot of people who start at Reason and end up elsewhere once their interests outgrow what's available in Reason.
Historically, Reason is easily the most stable full-featured music production system I've used. It may be different now with Rack Extensions, but its lack of plug-in support has made it more stable than pretty much any music production tools that provide plug-in support. (i.e. 3rd party plug-ins can significantly effect the stability of the host app)
As for learning curve, you might want to consider using GarageBand on the Mac if you want to learn the basics. If you don't have a Mac, consider some of the 'light' versions of DAWs that are out there like Reason Essentials. Or consider running the demo version of Reason before you buy anything.
The good news is, for anyone getting started now, the variety of tools both software and hardware are just staggeringly amazing. There's never been a better time to make music with your computer.
Good luck!