I'm trying to remember the frequency-history of upgrades I've made over the years. I jumped from 2003 Northwood Pentium to LGA-775 and C2D/C2Q in 2007. In 2011, I built my first Sandy Bridge, climbing aboard the Z68 bandwagon almost as soon as the chipset was released with motherboards.
I'm just 15 days short of a full four years with these configurations. I keep saying I "have an upgrade plan and budget," but I can't make up my mind whether to pull the string for a 4790K/skt-1150, a 5820K/skt-2011v3, or simply continue waiting and enjoying these old Sandy cores.
Your own OC seems to support those assumptions I had made about the SB-K processors.
I have occasional PC-tech discussions with my doctor, who had chosen a DIY approach to networking his office and clinic. He'd been more enthusiastic about picking parts and building PCs. I can't discount his current posture: "It can be like pouring money down the toilet." With that, he's addressing the "high-end" enthusiast obsession. He's taken to buying Dell refurb-retreads -- some with Xeon processors.
This type of thread pertaining to the Sandy K processors is among many which have appeared over the last year or so.
Z68 is positively ancient compared to X99. And I'd take 6 actual cores anyday over 4. If you kept SNB for that long, imagine how last X99 would last. The only real issue with X99 is it came out before M.2 and PCI-E were standardised along with USB 3.1. Then again there is always stuff coming out so . . . . .