I have looked on other OS forums about this issue. Few users also getting this problem.
i know that too. Let me explain you what's the real problems many users having
1. app crashes a lot: developers fault, they're developing a new revamped version. Currently in private beta stage and will be available in few days.
2. Delayed notifications: Microsoft's fault, all the notifications from any app is directed through MPNS(Microsoft push notification server) to our mobiles including those from WhatsApp. This requires a strong data connection between mobile and MPNS. And this is quite buggy. Sometimes you wont receive notification even if you have a good data connection. Also this service from microsoft provides no method to notify app-servers that notification is delivered to the mobile. And those app servers send this notifications multiple times in order to be sure that the notifications reached mobile. This is the reason why many users getting ghost notifications(repeated notifications).
3. Cannot send media files: microsoft fault. an os limitation. I guess you know that
4. Audio API usage: Microsoft's fault, for not giving an option to keep wi-fi alive after screen lock. Now that portico update provided this option, the new version of WhatsApp ditched this usage.(this version is in private beta now.). Audio API usage is the elegant and simple solution for this.
and for your satisfaction,
the new version of WhatsApp is far far better than current one and you'll get it in (ahem) few days. Wait till that.