I love Essie and OPI's formulas and find that they are more consistent than China Glazes formulas.
When it comes to durability, I find that OPI and Essie polishes will last longer than China Glaze polishes by 1-2 days. The funny thing is, there are some colors where OPI polish will last longer, and then other colors where Essie polishes will last longer, so it differs from color to color. I also found that China Glaze glitter polishes will last extra long.
However, with the combination of a high quality base coat and top coat, you can extend the life of your China Glaze polish very easily to last as long as the high end polishes. :)