MENBOONG :
i might bite the bullet and upgrade to the i7 simply for the added performance for video editing
Bottomline is that i5-6600K is the sweetspot for lighter video editing/rendering tasks. Depending on the programs you may use (some programs use video rendering, others does it via cpu and benefits from number of available threads) you may gain a performance boost by i7-6700K. That doesn´t mean i5-6600K performs bad - in fact, i5-6600K are faster in alot of tasks than the i7-6700K.
http://www.tomshardware.com/reviews/skylake-intel-core-i7-6700k-core-i5-6600k,4252-5.html
However, CPU isn´t the all deciding factor - ram and storage setup matters alot too.
If you´re opting for a faster chip, you rather want to look at the 5820k than the 6700k. They are similar priced and you get quad channel ddr4 vs dual channel, 15mb of cache vs 8mb.
If you´re serious about video/3D editing
You want a storage setup like this:
1) 250 GB SSD - For Windows + programs (M.2. SSD is recommended, 950 PRO from Samsung i.e.)
2) 120 GB SSD temp/scratch drive (any cheap will do, OCZ is often at a good price point)
3) 2 TB HDD for anything else. (look for 7200 RPM and 64 MB Cache)