I think one needs to go for only that service provider which can provide cash-less claims ... this is normally specific to the manufacturer, and sometimes the dealership also.
If you are sure that your vehicle will typically go only to the same dealership every time there is an issue, it is worth searching for this option, even if the premiums are marginally higher.
I have Chola for my wife's Innova, and am happy with the service so far.