I know my Chinese listening is not good, but I have not issues with the man a woman voices. Maybe the man sounds clearer but both are Ok, and I feel the experience of to listen one a voice and next the other very convenient. So bigger files, I don't think in my ears or handset will make a difference. But, of course, can make for other ones.
I also want to confirm the limit of the Palm Tungsten E2 is 1GB. So, I found from I started to use Pleco Beta 2 I almost run out of space on my 1GB card. It is enough for Pleco 2 and other many programs, but I is not to put the mp3 and video files I use to study more Chinese. So, I have just decided to buy a new program (PowerSDHD) to have enough room for all this files in a 4GB card.