I subscribed to the 3 telco lines - in terms of data coverage ( which is important for download, browse internet ) , my experience for the past 5 years , the best is Celcom follow by Digi. Digi at my place has no 3G only Edge , but I'd say even so it is equally good as Celcom. I has the worst experience with Maxis, which is  GPRS/3G signals dropping off while travelling in a vehicle - thought is my card problem, even no improvement after changing it