If I update from DVD to blu ray I have to be convinced it's a significant upgrade. Usually it's a Criterion with significant extras. That said, the only three commercial discs of film noir I have upgraded in that way are Nightmare Alley, Leave Her To Heaven and Kiss Me Deadly. All of the films in the original Warners and Columbia boxes, no need to go higher. Night and the City no, as my disc has both the English and American versions. I have upgraded a number of other films and not regretted it, notably the Kubrick films 2001, Dr. Strangelove and Barry Lyndon, all of which included a wealth of extras and dramatically improved visuals.

Some blu rays I've purchased to replace homemade copies were well worth it: The Killing (which also includes Killer's Kiss) and Sweet Smell of Success, which is absolutely stunning to watch in a Criterion blu ray copy.

FYI, I re-watched my copy of The Devil Thumbs A Ride that I taped onto DVD in 2005 from a TCM broadcast and it is amazingly crisp with good sound. I don't think I'd need to replace it even if a commercial version came out. But it is a shame that film isn't available for the masses. It's not Lawrence Tierney's finest hour, but it's close. I would still prefer Born to Kill on that count.