In my opinoin, it's a waste to go any higher than 56k. Depending on what type of music you're broadcasting, that may even be wasteful. Until everyone has DSL, Cable, or fiber coming straight to their house you are still going to have people with 56k modems who won't be able to even hear 3 seconds of your stream at 64k without rebuffering. So I guess what I'm saying is that it depends on how many people you want to attract. I broadcast at 24k to get more users to listen to my stream and so I can support more users on my main stream. (I only have 144k up and down on my IDSL) It doesn't sound bad for most dance music, but I've heard people complain with types of music with lots of highs. I played around with a couple of different settings before I settled on 24k.
DJ Derrick E.