Yeah, these things are kind of interesting, though I've taken them before and I know the results -- I can't reliably tell the difference between lossy files and lossless. If I ABX'd across enough trials of enough different files and listened hard enough, I'm sure I'd eventually run across passages I could identify as lossy, but I sure don't have any interest in that. I'd rather listen to music, and I know that when that's what I'm doing, I won't hear the difference. If I had better equipment, could I hear it, even when relaxing and enjoying the music? Maybe. But the other side of that is I can already hear bad mastering well enough that when it is bad enough, I find it hard to listen to. I'm not sure I want much better equipment!
I still rip everything to lossless, though. Hard drive space is cheap.
Tim