Pros: Improved TIM, Decent Silicon (compared to older haswell 4670K)
Cons: TIM wasn't improved that much
Both 3570K-4670K got delidded to save temps but the 4690K was advertised to have improved TIM so we don't have to delid anymore. This cpu hit 4.5ghz without needing to do any modding the CPU which is great when you want warranty. Also it was told that the Silicon is able to hit higher clock speeds compared to older haswell and with that being said I only gained 200Mhz overclock compared to my old haswell.
The only thing that makes this CPU amazing is price/performance for gaming. You are gonna hit 4.5Ghz with decent cooling making it even faster. Buy this if the price is good and you just want a gaming rig!
This processor TIM is not a major difference compared to older haswell. Sure its cooler but if you delid 4690K and add Coollaboratory Liquid Pro, temps drop down even more so this means if you are a overclocker like me and want that extra speed... you will need to delid this again, which means warranty is gone.
Right now as of 2015:
Recommend second hand or a good retail price. $299 is standard but do some research on CPU dates codes and what dates will give you a strong cpu to overclock high speeds.