I recently saw an old interview with one of the founding members of Propellerhead - Marcus Zetterquist - right here:
Part 1: http://www.youtube.com/watch?v=TwypkDGhV4o
Part 2: http://www.youtube.com/watch?v=B6Qy2kx-GIU
Something that he said in Part 2 (2:24) bares reiteration:
When we did Reason... there's nothing you could do in Reason 1.0 that you couldn't already do. It was just more fun and faster in Reason.
My personal feelings are that this clearly is still the case for the most part, and it keeps me here. Taking into consideration that the volume of people who are excited and satisfied with the course Propellerhead have taken is louder than the volume of those who aren't, I would wager that I am not alone.
I'm looking forward to Reason 7.0.