Hi, I have tried both. OPI is pretty good but it does shrink from the edges, at least the colors I've tried. But that issue is workable. CND, sorry but not a big fan. Partly because I do nail art and CND is a hybrid gel that can dry out before I'm ready to go under the lamp. Also, I have had trouble with it wrinkling. Gelish has the same issues as the CND because they are both hybrids. Both the hybrids I think just have to be worked with differently that I just have a tough time with.