I just swapped a 16" M1 Pro 16/1 for a 16" M3 Max 48/1, specifically because I'm now using Lightroom vastly more than when I bought the M1 Pro.
My sense is that the numbers above are about right. It definitely feels snappier in general, but Lightroom imports and preview generation are MUCH faster. I'm sure some of that is just the extra RAM, 16GB simply wasn't enough for importing and digesting several hundred 45 megapixel shots at a time. The wait until they were fully loaded with previews so they were instantly available was quite painful, and even with the M3 Max I can see all 16 cores fully loaded when it's working though a new import.
With the M3 Max and the extra RAM, it's of course still not instant, but the import/digestion process was much snappier, and was reasonably responsive when I clicked a specific photo before the preview was generated.
Long story short, I wasn't looking to upgrade, I'd been quite happy with the M1 Pro until I started doing more studio shooting and generating large batches of photos routinely - but it was clearly badly struggling with that increased load. The M3 Max with a bigger RAM bucket handles the same load nearly seamlessly.
The thing I don't have a sense of is what the split between the RAM upgrade and the chip upgrade is, so YMMV depending on your current specific configuration.