This is them side by side. You do get quite a lot of product with the revlon one compared to MAC. The shades in the flash photo don't look as close as they really are. It's so hard to find this magenta, purple, sheer shade and finally I think I have found an exact dupe!
Here is a swatch of the colors
If there is any difference it's that the MAC one is very slightly creamier. I do,however, prefer the Revlon one due to the fact that its not sticky on the lips like the MAC one is. But, my MAC Revenge is Sweet is about 3 years old! I know,I know it's expired but, I couldn't throw it away or use it up until I could find a proper duplicate. I hope this helps some of you out there who also like this shade!!