I'm saving money for a graphics card and I don't know if I should get the GTX 1080. My CPU is i5 6600k.
I'm afraid that there will be a bottleneck.
Is it worth it?
Yes it's worth it. You will enjoy it and see a small bottleneck in games like BF1 who can run many threads, but even with the bottleneck performance will be awesome don't worry that much about it like 95% of games won't bottleneck much