Thank you, Bob Fisher. Yes, I have heard of Bridge. I use Bridge frequently when I only want to review a test file without cluttering my Lightroom catalog. Bridge performs exactly the same as Lightroom when first rendering a RAW preview, regardless of whether processing the Canon, Nikon, or Fuji X- files I work with most, there is still a significant (1~5 seconds) delay over Photo Mechanic.
If you aren't willing to do the heavy-lifiting of researching your ideas before submitting them as answers or suggestions (albeit veiled in smugness), then please don't waste my time with frivolous posts. With that out of the way, if you have any informed ideas about why Adobe applications require so much time to render RAW previews relative to Photo Mechanic, I would be happy to listen.