I have a huge collection of OPI because they have a great range of colours and they generally apply wonderfully in 2-3 coats (sometimes needing more, or less). They last a decent amount of time without chipping but I find that is also more dependant on how well you prep your nails, i.e. buff, base coat, colour, top coat.
I'll keep buying OPI as they have the best selection of colours.
I have a 50/50 review for this.
When I go to a nail salon and choose an OPI colour it's last 2-4 weeks. I love their massive selection for colours! They have gorgeous matte colours, shiny and glitter formulas! So I'm really pleased with that.
But... my own OPI that I own are o thing compared they chip after 3 days wear and act like any old normal polish I own.
Tips: My tip would probably be go to a nail salon! Or mat e try a top and bottom coat. I definitely will be and update my review once have!