Well, I use Viber for most of my chatting (outside of Facebook anyway) but while I end up using Viber for video calling a lot, the volume is too quiet on it. Google Hangouts is better, but it always seems like audio and video are always a microsecond out of sync on that.
I'm sticking with those two though, I'm NOT running a boatload of messengers on my device. The selfie cam is great though.