Hello! This is my first comparison post. I don't have a massive collection of polishes so I don't often end up with two that are very similar (yet). As soon as I put on Stance though it reminded me of Purple Passion.
When you first apply Purple Passion, it looks almost identical to Stance. However when it begins to dry, it ends up a little darker and almost has a matte finish, while Stance is a jelly/creme.
PP is definitely more purple and Stance more fuchsia, but at first glance on my nails you can barely see a difference. It's a lot more obvious on camera. Stance is also much easier to apply. PP is a good enough formula itself, but can't stand up to Illamasqua.
Models Own retail for £5/14ml, and Illamasqua £13.50/15ml, so there's quite a difference in price, but Illamasqua definitely wins this one.