I find for MP3's, the best compromise for size/quality is 128kbps, latest EAC & LAME + a high fidelity DAE drive (like Plextor, Yamaha, [even Lite-On's are good there] latest models). That way, you can fit heaps more MP3's on your MP3 CD that you made for your car/portable MP3 CD player. Even though it is only '128kbps', it still produces suberb peaks if used with the above equipment, and good hardware and/or software decoders....
There isn't much difference between the above and the original (sound/quality wise) anyway
You can tell, but I can also distinguish the diff between LAME encoded 256kbps MP3 & my high-end Sony HiFi stereo system [:0]