This actually depends on personal usage and career, some pll they need keep call bosses, supplies, clients, they cant use whatsapp or wechat call, so 1000 mins is definitely not enough at all.

But for those who subscribed Amb68, but they did not call that much, better go for Amb38 and keep top up for internet quota more worth than Amb68.

Should be depends on area, mine so far ok le, download can maintain 1-2mbps