It should generally perform better the Core i3-2310m (2.1GHz) which is a CPU from 4 generations ago. I have somewhat old laptop with a Core i5-2410m, but I disabled Turbo Boost and limited the clockspeed to 1.7GHz due to overheating. Since I plan on replacing it I have not bothered to take the laptop apart to replace the thermal paste which should fix the overheating issue. Despite limiting the clockspeed to 1.7GHz (the i5-2410m can Turbo Boost up to 2.9GHz); I find that it is fine for using Excel and watching 1080p video.
Since the m3-6Y30 clocks down to 0.9GHz you might notice a brief lag once in a while when the laptop suddenly needs to something CPU intensive which would cause it to ramp up to 2.2GHz.