Wolfshadw :
Differing opinions.
-Wolf sends
Although I have huge respect for choosing high quality components, I also respect some people are on a budget.
In gaming,
i5-6400 vs Intel Core i5-6600k will have no significant difference in performance. The k-series chip may be overclocked but it will still have no significant gains when gaming.
GTX 980 TI vs 970 will however have a huge perfomance impact Reports shows that 980TI has 50-70 % better performance than the 970. http://www.pcgamer.com/nvidia-geforce-gtx-980-ti-review/
980TI will be good for years, and the i5-6400 won´t bottleneck it. 970 will however be short of videoram for upcoming titles, and you´ll have to settle for lower graphics settings to run smooth performance.
To sum it up, you get a better performance now and upcoming years with easier upgrade path for the same price.