On an average body of music though, they will average out to be the same. Many of the samples chosen were picked because they are difficult to encode and a good VBR codec will increase bitrates on those samples. On easy to encode samples or quiet passages a VBR codec will have _lower_ bitrates. This isn't unfair - it's just that VBR has an advantage because it can be more efficient (which makes it inherently better unless you are doing something like streaming that can't handle the fluxuations.)

This is precisely the kind of ignorance I'm talking about. Knowing people who claim to get headaches is not scientific evidence!

First, a few facts:

• Glutamate is an amino acid that naturually occurs in the body (as a neurotransmitter, for example).
• Eating glutamate does not affect the concentration of this amino acid in the brain (therefore, you can't eat it and cause a headache).
• Glutamate occurs naturally in many foods, including tomatoes, milk, mushrooms, peas, parmesean cheese, and seaweed, to name a few.
• Glutamate has been shown in scientific studies to help people with poorly functioning taste buds increase their consumption of food (the elderly, for example).
• Scientists have shown that taste receptors on the tongue respond only to glutamate and not to any other combination of sweet, salty, sour, or bitter. The taste has been named "umami", or the "savory" flavor.
• Glutamate was first identified by a Japanese scientist way back in the early 1900's. Japanese broth (dashi), which is as common as chicken broth in the west, is made from seaweed containing loads of glutamate.
• Monosodium glutamate is simply a convenient salt form of this naturally occuring amino acid.

Tongue experiments:
Try eating some very, very rich plain tomato sauce. After you swallow, you can taste a lingering flavor on the back of your tongue. It's kind of an earthy, savory, meaty flavor. That's the naturally occuring glutamate in the tomato. A minute later, place a few crystals of monosodium glutamate on your tongue. You will taste the exact same earthy, savory flavor from the MSG.

After you've identified the flavor, you'll be able to easily taste it in mushrooms, good parmesean cheese, meat broth, and milk. If you've ever have miso soup in a Japanese restaurant, you can definitely taste it from the natural seaweed in the dashi broth.

The caveat:
Some people have been shown to react negatively to monosodium glutamate (it is not an allergy). It's a very small percent of the population. Saying MSG is bad for everyone would be like saying peanuts were bad for everyone because some people are allergic to peanuts.

A few references:
FDA MSG - Safe
FDA - Some MSG Findings
Chart of glutamate naturally occurring in foods
Society for Research on Umami Taste