As usual, nice for the americans but totally useless for european players. When your normal rando team is like two russians, one german, one brit and one frenchy, voicechat is useless.
Will be turned off by default for me.
Have been playing a bit yesterday and today in my region, EU. So far, I have had overall a rather positive experience with voice chat, and I have seen no actual flaming happening yet. People are usually pretty silent, but when they aren't we have been able to make some very important shot calls and plays that normally wouldn't be possible.
For example, I made the suggestion to make a high risk, high reward boss capture when we had 2 tributes and the enemy 0 before hitting lvl 10 on Cursed Hollow. Normally, you wouldn't see people react to such a call in time, but everyone was instead quickly on board and committed. The enemy did actually spot us and tried to contest, but we managed to outplay them, and got both the boss and the 3rd tribute. All of this happened in an Unranked game and it was great. Little stuff like that has elevated the game to me in ways I didn't think was possible outside of Team League and regular premades.
VC has been fine for me aswell (on EU). Some people have thick accents but anything they typed in chat would " hev look somting lick dis" to begin with.