I think OPI is definitely better. It has a nice wide brush that will cover almost my entire nail with one swipe. It has great staying power as long as you wear a good base and top coat with it (of course a good base and top coat will help any nail polish to last longer). Anyway, my vote is for OPI.
I hope this helps you.
I find that OPI has a bigger brush, I have wider nails, so I do prefer OPI. It really depends on your nail shape. But sometimes, I buy an OPI color, and it is sometimes sheer which is disappointing. So far with China Glaze, I have found all of the nail polish colors to be pretty pigmented!
i love OPI!! my whole collection is consisted of it. i love how there are so many shades to choose from that differ slightly for different types of skin tones. there color palettes are incredible and i love that they have gift sets to purchase so its cheaper that way. Also OPI by SEPHORA has the collection of smaller nail polishes in about 48 different colors which is AWESOME for those getting started to want to experiment with the different shades
I personally find that China glaze goes on much smoother and dries quickly. China Glaze's top coat is the bomb! OPI has a nicer colour selection however, it goes very goopy after 6 months and I found it takes much longer to dry once applied.
Definitely China Glaze! O.P.I is the worst. Drugstore nail polish is better than O.P.I. O.P.I starts to chip the day after you apply it, even with a good top coat! NEVER BUY O.P.I. China Glaze is much better and has a good brush and stays on alot longer. They also have a great variety of color and are a bit cheaper!
Hope this helps!
Answered[ Edited ]
I own Original OPI and Sephora OPI and China Glaze and I love all these brands. In terms of duarability, I've worn all these brands for at least a week at a time before any chipping occurred. Honestly, you can't go wrong with either brand. OPI (both the original and Sephora lines) have a great range of color, their brushes are long and thin and wide, easy to control and apply evenly. They also dry pretty quickly. The original OPI brush is better than the one on the Sephora OPI line, it's easier to grip and the brushes are longer. Plus, there's a larger range of color, in fact, I believe that you can find a dupe of most of the Sephora OPI line within the Original OPI line. Plus, the Original OPI is often found on sale at many beauty supply stores. China Glaze also has a great range of color (I especially LOVED their Glitter line), their brushes apply color evenly and they cost about a $1 less then a bottle of OPI (if you buy the retail price). China Glaze polishes take a little longer to dry, but when they are dry they're really hard, sometimes I don't even bother putting a Top Coat over it. I've worn it without a Top Coat and it lasted me a week.
I'd suggest that you buy the Original OPI and China Glaze brands at a beauty Supply store like Ulta because they often have sales for buy 2 or 3 get one free or 50% off. Seriously, you can't help buying multiple colors at a time
I like OPI best! But if you change your polish often anyways, I would go with china glaze as it costs less. It also depends if you have natural or "fake" nails. I have acrylic nails and they "naturally" hold polish better than natural nails, so they both work great once applied. I do agree that the brushes OPI nail polish has are better and I like the way they apply better also. Once you get it on it doesnt really matter with acrylic nails. For the record I have about 95% OPI in my (large) collection and the other 5% is mostly china glaze.