How hard would it be to use the hardware statistics to get upper and lower bounds on the total processing power of the network? We could then compare these figures to estimated GFLOPS from the projects themselves, as reported in the monthly 'State of the Network' posts. I have been skeptical of the reliability of the latter values for some projects.

Well, I suppose I could get the estimates myself, but maybe it'd be faster for you since you already are familiar with the scripts.