Iam using this vodafone sim kerala trivandrum circle for about 8 years , since I didnt noticed any troubles regarding this operator. Vodafone sim is now in 4G also. Most intresting fact about this sim is that there are somany best plans are there in this sim for about these time. Iam recharging this sim once in every month so that iam getting many best offers like double data , double offers. So I suggest every one to buy vodafone sim.