I just purchased a refurb'd MacBook Pro 2.33GHZ, 15", 2GB, 120GB hd, Radeon x1600. Now I see that they have refurb'd 2.4GHz machines with NVIDIA GeForce 8600M GT with 256MB of GDDR3 memory $300 more. I am an architect and I frequently use 3D modeling animation programs such as Maya. Should I: 1) return the current machine and get the latest. 2) purchase NVIDIA GeForce 8600M GT 3) purchase a top-range graphics card (if then, which one?) 4) none of the above. don't worry about it. Thanks!