With my Maxxum 5D, I tend to avoid spot metering (if you are not very careful what you meter on, you can easily end up with an overexposed or underexposed image).
With it, I tend to use Center Weighted more often with it (it seems to be a bit more predictable...
How does Center Weighted metering behave with your A300?
Your first statement matches exactly what I said. Based on previous experience with SPOT metering, the mainsubject would be the only thing properly exposed. Everything else would be either over or under exposed depending on whether the subject was very dark or very brightly lit. The A300 does a wonderful job in this area.
Like you, I use CW 90% of the time.I only use Matrix when shooting landscape at full WA. As you stated, CW is much more predictable (including the A300).
The other thing you mention is noisedue to under exposure in order to prevent highlight clipping. Althoughat first it appeared that the camera was simply reducing the Ev by -0.3 or -0.7, I believe in the case of the A300 there is much more to it. The reason I'm saying that isbecause with the E510, Iconstantly had to under exposeby at least -0.3 in order to preserve highlights and by doing that, the dark areas became so darkand noisy that it spoiled thewhole thing.The A300 on the other hand,preserves the highlightsand shaded areas almost equally. I think the picture of the boy leaning of the shovelshows just how well the A300 handled the various levels of light.