Yet, I don't spend much time on them, because I show them to others only when I don't have a ★★★★+ photo to serve the same purpose. They often serveIf they're seen at all, it's usually only as narrative glue in slide shows.
I rarely do more than crop & straighten them★★★ photos or apply batch changes with Ctrl/⌘-Shift-V. When I do spend more than a few seconds on such a photo, it is in an attempt to raise them to a ★★★★+ photo.
This is my threshold for off-site backup. Except for home inventory and family photos, I don't bother to include ★★ photos in off-site backups, and I don't back-up ★ photos off-site at all. The idea being, if my house is hit by a meteor, I won't drop any tears over losing such low-rated photos. I'm willing to keep them around as long as it's "free," but I'm not going to pay off-site storage fees to maintain their existence through a disaster.3
Such is the beauty of photos in this rarefied class that I will display them long-term, knowing that I will not quickly tire of them. These are the photos I hang on walls and use as desktop backgrounds.
The higher the rating, the more redundant backups I have.34
In a folder of unprocessed photos, activate THE CHAINSAW (tthbbitrrrrrrr!), then turn off all the UI distractions by pressing F.45 All you should see is the first "undecided" photo in this folder, full-screen.
Now put your fingers on the 1-4 keys and your thumb on the X key.56 Taking at most a few seconds per photo, rip through the set, giving them an initial rating or rejection. Trust your expertise and go with your initial "flash" impression. If you find yourself dithering, it's probably a ★★★ photo; rate it and move on.
When all the photos are rated or rejected, delete the rejected photos: Ctrl/⌘-Backspace.67
I don't erase my filled memory cards on the road for the same reason.
This the sort of metadata we had before GPS tagging.
Low-rated photos do still get backed up locally, such as in whole-HDD mirrors.
I don't literally have 5 levels of redundant backups. I just mean that there are more copies of my ★★★★★ photos floating around than copies of my ★★★ photos.
In Lightroom 4 and earlier, F had a much more limited (though related) function.