I bought this after seeing The PolishAholics' Formula X Spam post. I've been looking at the gorgeous bottle for ages and since summer is quickly winding down I wanted to get this on my nails. One problem though; the formula stinks. Not smelly stinks either. It's probably one of the worst formulas I've ever worked with.
Kapow! is a bright and bold electric blue with shimmer that changes from blue to pink and then to purple depending on the light and angle. It's seriously gorgeous. A lit from within glow with the intense blue is really special. The formula was very sheer and it actually cracked on top of my base coat as it dried; the weirdest thing ever. I even tried starting over with a different base coat but the same thing happened. Both were ridge filling base coats though so maybe that was it. It took 3 coats to get it to even out and to give me some opacity (though you can still see some light through my nails at certain angles). The good news is it dries very quick because it dries down to a matte finish.
To smooth everything out and to get a nice glossy finish I applied 2 coats of In A Hurry Air Dry Top Coat. Sadly, this only held up for 3 days on my nails before half of it managed to chip off my nails. I don't think I will ever use this again. It's beautiful but the application and longevity sucks. I bet I could find something similar with a better formula.