I recently downgraded my mp3 rips to 128k (mp3 format). Portably, the sound difference isn't significant for me. The storage benefits are (significant), and my DAP gets better battery life & there is less wear-&-tear on the hard drive (fewer disk accesses).
i use 128 vbr aac on the ipod, transcode from flac on the computer. when i get a cdp though i'll go from flac to aac on the comp, too, though, as the sb live + px100 makes it so i can't hear any difference
I use 128 AAC VBR as well. For some LIVE stuff though, I use 160 VBR.
I CAN tell a difference between 128 and a CD, its just, to me 128 aac vbr sounds GOOD ENOUGH for on the go. Besides if I want lossless I'll bust out my cd player
128kbs sounds bad to me. I use LAME 3.97b2 -V 2 --vbr-new. I can't tell the differance between LAME and apple lossless on my iPod. There is no way i'd encode my music other than using this method. EAC and LAME 3.97b2 -V 2 --vbr-new is the only way to do it. Everything under that sounds bad and everthing above that is over kill imo.
I used to use 64 kbps, then I made everything 128, then I jumped to the world of 192/320 .m4a/.mp3/.acc. I can't tell the difference between all of them. 192 for regular CDs, 320 for my favorite songs/cds and live recordings.
Seriously it depends a lot on music. A few times I've been enjoying music to be shocked when I found out the low bitrate (last time this happened was a Tom Waits album). There have been other times there was obvious something was wrong, and then I saw the bitrate (last time was with Lucinda Williams).
No one is claiming a Ramones disc needs to be lossless.
And of course location/environmental noise plays a big part (this is a portable forum). The obvious extension to this conversation is the large number of satellite listeners that are satisfied with the equivalent (XM and Sirius use difference codecs) of around 48 kbps AAC+. It's quite horrible with headphones or a quite area, but in your car, it's quite fine.
Also while 128 AAC should be better than most 128 MP3, 128 ABR LAME comes very close.