When you sign up for WeChat, they want your mobile phone number. That means Tencent and perhaps the Chinse Government know your whereabouts and what you are communicating at any moment in time -- in the present or the past. No thanks.
WeChat has started to get some mometum in India too. The firmstars have been promoting in advertisements. But on ground everyone is still on WhatsApp. What I dont like about WhatsApp is anyone who has your cell number and has WhatsApp installed can contact you, eve make you part of their group whether you like it or not. And then you have to either keep viewing the messages or block the person. Too annoying sometimes. Now that facebook has acquired it, dont know whats happening at the backend.