Your over all build is great no need to change all the components. i5-4690K is a great CPU and is still a great performer. Don't waste money on upgrading to i5-6600K there is no big difference.
Your over all build is great no need to change all the components. i5-4690K is a great CPU and is still a great performer. Don't waste money on upgrading to i5-6600K there is no big difference.
The only thing I felt like changing in your build based on quality is the PSU. Went with far better PSU with this next 3-4 times you upgrade(if you upgrade this regularly) you can save money on PSU.
Included a SSD as you don't have. 250GB will be enough to install OS and and have some games on it. If you are still left with good enough margin then you can go for bigger SSD(depends on you).
Upgraded the RAM to a better 16GB 2400Hz model.
Now the biggest upgrade in your build you are getting is GTX1080. You will see a big difference in gaming over the R9 290X.
There is no need to change anything else in your build.
i5-4690K is a great CPU and is still a great performer. Don't waste money on upgrading to i5-6600K there is no big difference.
The question is more along the lines of why to stick with older technology. Sure, the i5-4690k is a great performer like any modern i5. The things is... there is no cost savings going with the older technology and yes, Skylake does offer more performance than Haswell Refresh. Not much reason to go with LGA1150 and DDR3 IMHO when build a new rig...
If he is building entirely a new PC then going for Skylake makes sense but he is only upgrading which means he already has those components. So going for new CPU and Motherboard doesn't make sense
If he is building entirely a new PC then going for Skylake makes sense but he is only upgrading which means he already has those components. So going for new CPU and Motherboard doesn't make sense
If OP had something like old gen i3 or AMD series then I would definitely recommend a completely new build. But with a strong CPU like i5-4690K a CPU upgrade doesn't makes sense