I think there's enough in 2012 to justify jumping from 2009 to 2012. 2010 and 2011 where rough years but there are things that I've come to depend on in the newer versions I wouldn't want to go back and I wouldn't want to try and code those myself. The differences between 2009 and 2012 that I have a hard time living…
I agree with renderhjs when it comes to using Nvidia cards for 3D-applications. ATI usually causes more trouble and has compatibility issues, at least from my experience.
Green = Problem Solved Didn't want to be one of those guys who resists change. I usually try to embrace it. So I forced myself to move up to 2012. I had some issues with Nitrous, switching to Direct3d fixes most of my problems. But then Direct3d has its own?! Maybe some of you guys can let me know how many of these issues…