YOUR-SAY: DOUBLE-CHECK IN WHATSAPP

First of all, I think that this new option of WhatsApp is a nonsense because before, you could know if your message had been read, looking at the last connection of the contact. As well, you can know if your message had been sent it had one check, and had been received it had double check. 

Secondly, to my mind It's useful in the WhatsApp groups because in this way you can see who has read your message and who hasn't. Before, in a group you couldn't know it. 
In the audios, the blue double-check used in the past to know if the contact had listened the audio. 

I think that this can have problems because there are people that are very obsessed looking at their whatsapp all the time and with this new option it will be more catching for them. Moreover, people can get angry if they know that their message had been read and the contact didn't answer them.

However, technician of Whatsapp are working because you can deactivate this option like you can do with deactivate the last connection. But if you decide that the other people don't know when you had read the messages you can't know if yours had been read. I personally think that you can chose activate or deactivate this option is a good idea.