Just Had an Amazingly Clear Conversation Using Whatsapp Voip and Tmobile Global Data
A friend of mine is in the UK now with his Tmobile phone (Moto x Pure 2015), using the free data roaming.
We just had a very clear conversation using the built in VOIP in Whatsapp. About twice in our 5 minute conversation there was a 10 second gap where we could not hear each other at all - the rest of the time it was very clear, no voip stutter or the like. It seemed that the quality was binary - either it was very clear, or we couldn't hear at all.
I was surprised that there was no noticeable latency - given the high ping times that I have seen on Tmobile while roaming.