I have a feeling MFAA is going to be another gimmick that doesn't gain anything.
photonboy :
Update:
The R9-290 is cheaper and has free games so it makes sense to a lot of people. However, we're discussing NVidia solely it's hard to recommend anything below the GTX970 due to the large performance difference and significant changes. As well as the 4GB of memory which will be needed.
3GB is enough for now but games are starting to use more. I stand by the suggestion of the GTX970
since the OP wants to use shadow play and it is comparable to the 290X. The GTX770 is a downgrade
from a 290