I had Reason 3. I had been meaning to upgrade for a while. Record (the new audio DAW software from propellerhead) is available for $150 to people who own Reason 3, AND that includes a free upgrade to Reason 4. Search for "Record for Reason Owners".
Record and Reason 4 work together seamlessly as one program. I used to use Pro Tools, and I'm happier now that I'm using Record. It's really well designed. I can't imagine a better software combo to own for a solo recording artist, whatever kind of music you do.
As far as the upgrade from Reason 3 to 4, you get a new synthesizer (Thor) which is pretty cool but not essential. The sequencer is a bit different, which I think is a definite improvement.Get more detail about Propellerhead Reason 4.0 Upgrade.
