This was partially part of the "Thank you for coming to Fanimecon 2004," "Maria-chan Appreciation Purchase." Why partially? It came up when I searched for Yamamoto Maria, but I bought it not because she was involved in it, but because it was a chance to get talks by a whole bunch of different seiyuus.
There are some interesting discoveries, like how Ikezawa-san is a scholar of sorts. I knew she spoke multiple languages, but from what I can tell, that's just the part of the bigger picture.
Some of the talks are pretty interesting, but some are pretty boring. I can't really agree with the "Best" portion of the title. I bet they could have chosen better ones if they tried harder.
It's not all that expensive, but it's definitely not for the regular folks (as in non-seiyuu-otakus).
