Forgive the ignorance of a brass player, but I was wondering why wooden reeds are considered to be so much better than plastic ones. It seems to me that a reed that doesn`t wear out would be pretty cool.

Because plastic reeds defeat the purpose of reeds, which is making the musician spend 80% of his income on crappy reeds.

Wooden reeds typicaly have a much better tone, and play better than plastic reeds. Of course, it depends on what kind of plastic reed you have, I have 1 emerald reed or something like that. It plays louder and jazzier, but is harder to control (though you can vibrato more and smear more on it IF you CAN control it) the lower notes tend to be tough to get out without going flat, and its almost to jazzy of a tone.

Good cane reeds give you the best tone, I think. The only drawback is that good ones are expensive, and you need to replace them every 2 or 3 weeks, depending on how often you play them. Synthetic reeds (plastic, fiber, etc.) can last more than 10 times as long as cane reeds, and this is a much better deal for your budget. For example, a box of 10 Vandoren bari reeds can be more than $70 (aah!!). A Legere synthetic bari reed is only $23, but it lasts a lot longer. I use Legeres for playing the bari not only because it is way cheaper, but because cane reeds for bari have a much shorter life, due to their size. Bari is also my secondary instrument, so I don`t worry so much about tone quality.