Finally I bring you this comparison that a lot of you asked for. Both of these polishes were released this fall. As you can already tell from the bottles, they are different. OPI goes more blue, on the other hand CND more green. There is also a difference in opacity, you can go just with one coat on CND but you need two for OPI. The colors are so different that I think it is worth having both :)
Here is how they look with Teal Sparkle:
