I just went from an i5-2500k at 7.5 to an i7-2600k at 7.6 (both at stock speeds). Just paid $70 for the upgrade to get a 0.1 WEI score
Well, I didn't do it for the WEI score. I'll be using my PC for more CPU-Intensive applications and games.
I'm using this with an MSI P67 motherboard, 16GB of G.Skill Sniper DDR3 1600, GTX460, and OCZ Vertex 3 120GB + WD Caviar Black 1TB. Sometimes the other components can affect your WEI CPU score.