Hey Tom,
If is not asking to much, and I know that this is an old post, but your system is very similar to mine and maybe you can help me make a very informed decision here.
I am have a macpro 3.1 SSD120 will upgarde to OWC SSD 240GB 16gb ram running a gt120 with a gtx285 video card on OSX 10.6.8. will upgrade to mountain lion in the next few days. May dilemma is, I would like to run AE CS6, Davinci Resolve 9, Final cut Pro but looking to change either to Smoke2013 or Premier Pro CS6 and also will be going to school to learn and use Maya. I was ready to buy the QUADRO 4000, but I call Blackmagic today to get an idea if the Quadro was the best for it and the Support person suggested the GTX680 according to him it runs without any need for change on macpro and is faster then the quadro.I look at the specs on NVidia site and the GTX Seems more powerful, but i am concern with compatibility issues is a gaming card and is it really faster when it comes to After effects, because I pretend to be using After effects more then any other program. What is your advice if I am to run all this program should I get the GTX680 or the Quadro 4000? and if possible please let me know why you think that is the best option. Thank you in advance.
Regards