I have been using Master card from last 2 year befor that I was using Visa, allthrough their is mot much difference in the Mastercard and the Visa both are good in use.
The facality that have been provided by the Mastercard is worth of using and I Nomally use Mastercard for all my online transiction and also for the shoping the charging rates of the mastercard is normal.
I would recommed you to use it.