Originally Posted by iDave
Personally, I doubt it's worth getting only half as many songs into my iPod.
For the record, because of the way the songs are compressed, 256Kbps songs are only 10-15% larger than their 128Kbps counterparts. Despite being twice the data throughput. So you're not losing "half" of the songs. But still gaining quite a bit of improvement on the audio quality.
To answer the OP though, it all depends how you listen to your music. If you're just using your iPod and a pair of $10 headphones, then no, the extra Kbps will not really make a difference. You can't hear every soundwave on the spectum with such headphones. Bass especially.
But if you frequently listen to music on your computer's desktop speakers, home entertainment center, or through a high-end car stereo system, then yes, you'll notice a HUGE difference in the 256Kbps songs.
In my own research, while I can tell the difference in every bitrate compression increment from 56Kbps all the way up to lossless, I believe that the jump from 128 to 256 is the most significant. This is because the bass is essentially removed from any song under 128Kbps. So when you play 256Kbps songs on a good stereo system, you instantly realize how "hollow" the song sounded at 128Kbps.
Now I'll admit I'm something of an audiophile, so even 256Kbps is a bit low for me. However, I can still respect the quality improvment from 128Kbps.
The biggest advantage to iTunes' 256Kbps songs though is the fact that they're DRM free. Meaning that you can copy them as many times as you want, play them on as many computers as you want, and never be limited to one iPod. the 256Kbps is really just a bonus.
Sorry this was long winded, but hopfully that clears things up for you.
To sum things up, yes, the quality improvement is worth it.