"My interest in a 900 Mhz Duron has more to do with efficiency, stability and bang-for-the-buck. "
You will be hard pressed finding any other cpu offering that much "bang-for-the-buck" as any Duron. As for stability, not the cpu, but the motherboard would be a concern then. The cpu itself is as stable as anything (never heard of unstable cpu's anyway), but you probably want a quality motherboard. I presonally like my MSI board very much.. its rock stable.
---- Owner of the only Dell computer with a AMD chip