If you're going the route of Local SIM make sure you take ID with you as well as they have some very strict rules about proving your identity before handing over a SIM.
A passport is suffice, but I left mine in the hotel and had to give my drivers licence details and 2 credit cards I think? They have a strange points based system for what types of ID they accept. But I agree with above, if you're staying there long enough then a local SIM would be far cheaper and stress free than roaming.