I just played online with my friend last night, the voice chat works just about perfectly, but voices seem a bit low, I'm guessing a headset or at least headphones would help.
We tried a lvl 100 battle, which bumps all of your Pokemon up to lvl 100, I assumed that would even the playing field, but it didn't seem to do much of anything. All of my friend's Pokemon are about double the lvl of mine, and it showed during the lvl 100 battle, so I don't know what the point is.
There's a lvl 50 battle and free battle (all Pokemon remain the same) as well.
My friend code: 1117 6711 9638
Name: Steve