Just did mine, 40°C lower on one of the cores . If I average temps from all cores before and after the mod, then it's 79.25°C before IHS removal, and 59°C after IHS removal. That's still 20°C difference, which is quite amazing. I just got a really bad chip out of the box. It couldn't even run stock voltages because one of the cores hits over 100°C. After undervolting to 1.07v @ 4ghz OC, one of the cores still hit 98°C, so this mod was pretty much required for me to get good temps.