Didn't attend, but saw the Miku concert though the stream. It was awesome packed and delivered straight to brain.
If they made a concert in Europe I'd by a ticket in a heartbeat, seeing as I live there.
I did follow the NND booth stream though, and saw many awesome cosplays.
<3 meltdown Rin.

Shoujo Kara Shoujo e Rather Tame
Nozomi Ero-Cosplay by Rin Higurashi Highly Cheeky
Dead or Alive Xtreme 3 Unveils Kokoro
Senran Kagura Estival Versus Trailer Busty As Ever
Genkai Tokki: Seven Pirates – “Much Treasured Chests!”