I've lost confidence in privacy coins at all. I still have some investmens in them though. A very important thing to consider about privacy coins is government regulations. It looks like in 2018 officials from all over the world will investigate crypto. And the thing that govermnet hates the most is anonimity. I will expect more governmental FUD focusing on those privacy coins. More FUD -> fewer new investors -> less gains. But this is only my opinion and as always check things and make decisions yourself.