A GTX Titan is not worth $450 as a gaming card. Factory overclocked GTX 780s are faster and you can get one used for around $200. The Titan is still a good workstation card though.
No bottleneck. Not even a little one.
If you want to spend that kind of money on a gaming card go with a GTX 970 or GTX 980 as both are faster than the Titan.
I am aware of the 970's and 980's, but in my country ( located in East Europe ) the cheapest 970's are around 425$ and the cheapest 980's are around 600$.
That's why I'm considering the Titan in the first place. And it still has 1.5 years of warranty!
Edit: After further checking the cheapest 970 is 480$, and I'm also on a set budget.