I have a gold bronze crackle polish I use over a lighter color polish that is multi color of metallic, but lighter than the crackle.  It is a very nice effect.  Make sure you use a lighter color underneath so you get the crackle effect. Black is also very good.  I use it over a light royal blue polish.

You will really like the effect.  I get lots of compliments.

I think it depends on the colors you use.  I've seen some girls who rock it but it can look really tacky too. i would say be careful!

I find that with the right color combinations, the crackle effect can look really rocker chick chic.  However, the minute you get a chip on the tips of your nails, it's time to change the polish.  I've created some really awesome looks with the crackle polish, including a pink and white zebra print, a leopard print using a bronze base, metallic bronze crackle and a black polish pen, and a myriad of other manicures.  It's all about your personality.