just my personal opinion, I get the 980 TI, its almost a Titan x with half the memory , The titan has 24 multiprocessor units, the 980ti has 22 and its the same Maxwell footprint as the titan.

a review worth reading
http://hexus.net/tech/reviews/graphi...ce-gtx-980-ti/

my past experiences with Radeons has not been good so I steer clear of them now, so I am biased.