The Nude, clear version, makes the 6S+ even more slippery. After handling it for a few minutes, it seems to draw skin oils out of your hand and adds an oil slick on top of the slippery. Then it looks gross and always feels like it's in need of a cleaning. Worst case ever...
Longtime favorite is the
Incipio NGP, strikes a balance between device protection and keeping added bulk to a minimum.