The answer to this depends on how well your 2700K or 3770K can overclock. My 2700K and 3770K both can do 4.8ghz 24/7 at a reasonable voltage, but after that it skyrockets and isn't worth the long term degradation. So yes, my 3770K beats out my 2700K. It also gives me PCIe 3.0 bandwidth, a better IMC (though I don't care for that since I undervolt at stock 1600mhz), lower power consumption, and lower temperatures after delidding (compared to the 2700K at the same frequency).
My 3770K feels like a fine tuned 2700K. They're both awesome chips, but if you're looking for performance, keep the 2700K. I wanted PCIe 3.0 bandwidth to open up the Titan SLI upgrade path (8x at 2.0 bottlenecks them), hence my upgrade.