I hit transparency before either with my current equipment so can't test.
Considering though for future equipment.
Anyone done a few trails with them and redbooks?

I didn't perform any tests, but I would believe both archieve transparency on 99+% of the tunes out there.

Both are transparent to me too. I don't even have to try. I know the limits of my hearing. (which are quite crappy, BTW)

I think anyone who is interested in 320kbps is also interested in which one fails more often in stress tests and how badly.
It's a bit weird attitute that you don't even have to try... (think of spahm.wav with Liquid Audio AAC for example)

I think we should do more AAC quality tests, the interest in AAC seems to be skyrocketing now that Apple launched the music service. I've been very busy recently, but I'll do some more extensive testing with Quicktime 6.1 AAC soon (or 6.2 when it's released for Win if there's an improved codec)

Also what interests me is whether the QT AAC quality has improved since the ff123's 64kbps test, though it's better to leave 64kbps for AAC-HE anyway.. Wonder when Apple will start using it.

I don't have to try for the types of music I listen to. If people that enjoy spahm want, they can do the test for themselves.

Besides, as I already said, my hearing is crappy. Not only that, I have shitty $12 headphones and a SBLive!

On the types of music I listen to, and giving my hearing abilities, and giving my gear, anything above 192kbps in MP3, MPC, AAC or OGG is overkill.

And no, I don't expect to buy pro gear in the future. Much less I expect my hearing to improve.

Regards;

Roberto.

http://docs.info.apple.com/article.html?artnum=93052

Yep