How many files?  Over 50,000 files
How big are the files?  web page files..html and cold fusion so they are not big
How many changes?   ...about 20,000 changes
How often will the changes need to be made? ...just one time and the script takes 20 minutes to run
How reliable does the process need to be? ..very reliable

If the process gets interupted by system failure or other unforeseen eventuality, do you need to know which files were
processed and which weren't? If some files were re-processed, would this be benign repetition? ..files could be reprocessed and this will be run during off hours
How fast does the process need to be? ...speed shouldnt be too slow but doesnt have to fast..main thing is what I have now does the job and has SOME effiency