What is Better GPS System, Car GPS like Delphi Nav 200 or Phone GPS like Nokia 6110?

I want to Buy a GPS system and want to know that which is better GPS system and more accurate one. Is it better to buy a dedicated car GPS like DELPHI NAV 200 or a Nokia 6110. And also as both of them uses different map source DELHPHI uses mapmyindia and Nokia uses satnav so which is better source of maps in India?