Long story short, thinking about handing down my current gaming PC's CPU+Motherboard to my little brother and buying myself a new CPU/Motherboard.
I currently use an overclocked i5-3570K @4.5 GHz. At the time I bought it, there really was no reason for me to spend $70 more for the i7-3770K, which basically extra $$$ for a slighter higher clock and hyperthreading.
Fast-forward to today and I start mucking around with twitch streaming, first thing I noticed was: damn, streaming at 1080p is CPU intensive, which is very detrimental when I'm playing games such as Guild Wars 2 that are very CPU bound.
However, I'm honestly not sure how much hyperthreading will actually help in that scenario.
I should also mention that I tend to multitask a lot with my six monitors and I do program heavily in Visual Studio 2013 for work.
Really, all this boils down to: is the i7-4790K worth the $70? (only $70 extra cause I live just a mile away from a Microcenter)
If there is just a 10% improvement, it'll be worth it in my book; I'm not exactly hurting for cash right now, and all I'd be replacing is the motherboard and CPU.