Depends on if you're willing to overclock. I got the Sandy Bridge version for the raw overclockablility. Performance wise it's about 15-20% less performing than Intel's latest, but if you take overclocking into account, Sandy Bridge is far superior to the junk Intel spewed out ever since (4 years).
Basically, if you don't need VT-d on K-series CPUs and you're into overclocking, Sandy Bridge wipes the floor with every generation since.
I'm still using Intel's boxed cooler and I'm at 4.5+Ghz (with Turbo Core up to 4.8Ghz) on all 4 cores with HT enabled. The latest generations are ever so slightly better at stock rates, but they overclock as locked i3s, which is to say not at all. Good luck trying to get newer generations at 4.7Ghz even on watercooling.
Basically, if you like overclocking, you're better off with AMD CPUs that Intel's newest and "greatest", they're simply worthless overclocking-wise.
But if you're an enthusiast, and especially into insane performance (through overclocking), Sandy Bridge will NOT disappoint.