Nick, the 'perfect' pitch you can acquire is unlike traditional perfect pitch, in that, you don't get so sensitive that 2 cents off will give you a headache, but you get adept at recognizing and remembering pitches quickly and accurately. Just like anything it takes a lot of dedication and hard work, and because of that, most people don't 'buy into' that product. But the product is only one method of learning, it works by associating pitches with colors, so that instead of just remembering a pitch with your inner-hearing(tough to do) you remember a color(easier to do) and then when you hear a pitch you think of that color, which tells you what note it is.
Sure, that's one way of doing it, association is a great way of learning, but it's no magic key, you still have to work hard at it.
Acquired 'perfect' pitch *is* desirable because in the process of obtaining it your relative pitch improves greatly, and ultimately you end up with not only superior pitch recognition skills but you also improve your relativistic skills too.