Whether there are advantages, but there is disadvantages too.
The main problem is updating problem.
When WhatsApp Official recieves update, GB WHATSAPP also gets the update. But the problem is on updating GBWHATSAPP. Because when we click on update, it redirects us to an Arabic site. Though there is translator to translate the languages into English, many people don't know how to use translator on an webpage. So I found it is the main disadvantage of GBWHATSAPP. We can update the official whatsapp on playstore with less data and time spending. Apart from the disadvantage of GBWHATSAPP, we can rate it as the best customisable WHATSAPP ever till date.