As someone who has used stick on nails quite a bit, with the separate glue that you end up with all over your fingers etc I loved the idea of these, no glue needed! At last! You simply peel off the back and press them on, simples! They're already painted and not too long, I did file mine back as they were a bit long for me (I don't like nails too long).
I'd bought them as we were going away for a few days (to a funeral), and my nails were horrendous, so I bought some purple ones and these black ones (don't worry I wore the purple ones to the funeral just in case you wondered) - they were really easy to apply, but, and it's a very big but, they didn't last any where near 7 days like they said, well it says 'up to 7 days'. I know Sprinkle of Glitter loves them, and they last really well on her, so I'm guessing maybe it's because the shape of my nails, but I struggled to get them to last more than 24 hrs before coming off. I applied them as they said, pressed down really hard, did all the bits I needed too, and even filed them back, but they just didn't last. And at over £7 a pack, I was less than impressed <-- see what I did there? :)
So in short, I wouldn't buy them again, I will use up the black ones at some point but as I have acrylics I'm in no rush to do that.
Have you used Impress? Did you have the same experience as me?