WMA9 (not Pro) vs. AAC for portable players Options

[salvator]

Hi,

I'm basically a newbie when it comes to various audio files and codecs. I'm in the market for a smaller capacity HDD player (read: lighter, smaller and cheaper) and I'm trying decide which is best. Basically, my options are the Rio Nitrus (4GB) or the iPod Mini. So, I'm interested in finding out the difference between WMA and AAC. I checked out Roberto's 64kbps test but I was wondering if anyone has any guesses on how things would be different if the comparison were conducted, say, at 128kbps and if WMA weren't encoded using a variable bit rate. Somewhere I picked up the impression that some of the artifacts in the WMA files may be due to poor implementation of the variable bit rate. It would be GREATLY appreciated if anybody could offer me a synopsis of all the accumulated wisdom in the various threads here, since scouring all the posts here would take me a very long time. Also, I'm interested in possibly doing a listening test of my own. Based on Roberto's "128kbps AAC codec challenge", the QT encoder seems best. Can anyone tell me if this is available for WinXP and if so, where I could get it?

Thanks,
Colin