I have a 3 year old MacPro, dual core, 2.66gh, 5gb memory (yeah, I know I need more). I took this morning's card, and ran it through my new, then my old workflow.
I have Lightroom set up to apply metadata and a global develop setting on import. It's the same settings I use in my old workflow, which I perform manually. I had a card with 118 images. I inserted the card and set the stopwatch.
Time to ingest all images: 4:25. Time to finish previews: 29:21. I edited during the preview build, deleted some images, renamed and captioned the take, and renamed the files manually.
Then I loaded the card again, and let Photo Mechanic handle the ingest. It took 1:21. When it was done ingesting I reviewed full-screen images (the RAW jpg, unprocessed), and deleted the bad ones. Then I manually renamed the files, applied my metadata template, and captioned the take. this took another 1:23.
Then I opened Bridge (CS5) and pointed it to the folder. I applied my two develop presets, a camera profile and my global adjustments. I waited until Bridge processed and built previews, and stopped the stopwatch.
Total elapsed time from card to finish: 5:57. 23 minutes faster than Lightroom.
I think this workflow experiment is over.