I'll agree with Pipeline and Chessrock on this issue. These mic shootout (or any other gear shootout) CD's have limited value. There was one recently that supposedly showed the Mackie preamp to be equal or superior to the $2000+ pres.
But as Chess and Pipe point out, if you are careful about how and what you record, you can easily blur the differences between cheap and expensive gear. In a real world situation where the gear is being pushed to it's limits, that is where the differences become much more noticeable.
The best judge of a particular piece of gear in the recording chain is often the artist/performer. They are intimately familiar with the subtleties and nuances of their sound, and it's much harder to "fool" them than your typical listener.
I'll give an example: when I first bought
my AT 4060, I put on some headphones and spoke into both the 4060 and a Lawson L47mp. On just my speaking voice it was really hard to tell a whole lot of difference. So, in theory, I could have concluded they were roughly equivalent.
But then I brought a "real" pro male vocalist and had him record some tracks using both mics. Then I played back the various alternate tracks without telling him which mic he was listening to, and asked for his preference. Interestingly enough, he picked the L47 track each time (usually with a strong preference). Although to my ears the difference was not always obvious, or at least, obvious which was "better", to someone who was an expert in hearing his own sound the choice was clear-cut.
That's why the shoot-out CD's are flawed - because we are listening to voices (or whatever) ONLY on the CD - we've never had the chance to hear them "live", and our only familiarity with them is through what we are hearing on the CD. So judging what they "should" sound like is problematic. As we all know, sometimes the "flaws" of a particular piece of gear just happen to match up well with the "flaws" of the sound source to create a serendipitous combination. I'm sure somewhere out there is a vocalist who sounds killer singing into a D112. But that doesn't make the D112 a "great" vocal mic for everyone else.
That's why i maintain the only true way to judge a mic or preamp or anything else is to use it on a source you are intimately familiar with, preferably in your own recording environment. That's how I've chosen compressors, reverbs, or just about anything. Personally, I think demo CD's can sometimes be a useful tool for choosing a synth or keyboard, but that's about it.