Audio Elitists are so annoying.
A good rip to 320cbr mp3 is just fine, especially on average equipment like 99% of us own. I run an emu 0404usb to my Grado SR-225s, and this ost in 320 sounds just fine. Obviously, the lossless one sounds better, but its not like night and day or anything. I don't know what sennheisers you have, but unless the answer is "HD595 or above", your Senns likely aren't awesome enough for you to be able to tell much of a difference.