I bought a load of the magnetic polishes from 17 when they were released last year. I hardly wear the though because I find they chip really easily and I got tip wear quickly with them too. However, for a night out they are great.
I used the dark green magnetic polish and topped with Rimmel's Matte top coat:
The magnetic polishes dry fast and I find the 17 products easy to work with, I think this might be because of the cap. The cap comes away from the lid of the polish bottle which I find makes the whole process less fiddly. The cap has a nifty lip which you rest near the cuticle. This means there is less chance of the magnet touching the wet polish.
Have you tried magnetic polishes? What are your thoughts?