Keith,
> Does there currently exist any kind of script that can be run on
> Postgres to conduct a complete feature coverage test with varying
> dataset sizes to compare performance between functionality changes?
No.
> If not, how many people would be interested in such a script being
> written?
Just about everyon on this list, as well as Advocacy and Hackers, to
judge by the current long-running thread on the topic, which has
meandered across several lists.
-Josh Berkus