Mike G wrote: (and why people like Ronnie and Stevez can pull it off in conditions where I get an amber cast at best, even with some p'shop wizardry on the back end).
I missed this the first time around.
As others have mentioned, post-processing flexibility is one of the most important advantages of raw. You can also usually eke out a good bit more dynamic range (the range of tonal values between pure black and pure white) shooting in a raw, coaxing detail out of highlights that would normally be clipped in a JPEG capture, but I won't go into that.
Your post about the amber cast is what I want to address. With a JPEG capture, if you don't have your white balance set correctly, there's only so much color correction you can do before your file starts to break down. As you've noted, you have some captures with an amber cast, and even with Photoshopping on the back end, you haven't been able to quite correct them. If your camera is set to daylight WB, and you're taking pictures indoors under an incandescent light, you're going to get a strong amber cast. You can correct a bit of this in post by shifting the white balance towards blue, but if the cast is strong enough, there's just not enough color data in your file to preserve the colors in the scene, and you'll get all sorts of weird blue and magenta casts. You're basically screwed if you want to preserve your original color fidelity.
Now, when you shoot raw, it doesn't matter whether your white balance is set to 2000K (deep incandescent) or 10000K (high altitude/cloudy/very blue light) or whether you've correctly adjusted for green/magenta values (fluorescent light). The raw capture records exactly the same sensor data no matter how your camera's WB is set. What
does change is the little bit of metadata that's tagged onto your file, which tells your raw file convertor how to process your file. It takes the WB data and then shifts the color data accordingly. This means that even if your white balance is completely off, you can basically go back and adjust after-the-fact, and get exactly the same results you would have had you set the white balance correctly the first time around.