iMac i7 and GT750M - enough for video editing

I'm thinking about buying an iMac 21,5 inch. It would have an i7 QuadCore (3,1GHz up to 3,9) with a GeForce GT750M 1GB graphics card and FusionDrive.

Would this be enough for After effects/Photoshop/Adobe in general? In After Effects, I create things like intros etc. So many effects and stuff. With my current computer (i5 and GT640M 512MB) it judders very often. Each frame has to load for a pretty long time. And rendering lasts hours. Will the i7 and the better graphics card (and maybe FusionDrive?) improve this so that I can work better with it? And is the improvement noticeable?

Also, I heard about CUDA in AE. With my current graphics card it doesn't work. Will it work with the new one?

Thank you