I've just recently been combining Photolab with Darktable.

DeepPRIME really is a killer feature. It produces images that are basically noise-free without turning the whole image into a smooth featureless blob.

But I also really like Darktable's Filmic RGB module and colour management (you can output P3 images and actually make use of the wide gamut displays that nearly every modern device has).

So I've taken to this process:

- Cull my images and putting everything but the ones that make the cut into a "Rejected" folder. I used FastRawViewer at first but I've warmed to Digikam.

- Run DeepPRIME and DxO's optical corrections with Photolab and export a DNG.

- Do final adjustments and exports in Darktable.

Basically, Photolab allows me to use Darktable but skip Lensfun (which others have mentioned is a bit of a weak point in Darktable) and push my shadows as far as I want without noise.

I am also on PhotoLab and have been very happy with it, the killer features for me are the spot removal tool and the perpetual license model. Darktable would have been able to satisfy both of those features, but when I tried it years ago, I had to go back to the menu to select the tool for each spot I wanted to remove and it was just not workable. Darktable had many interface annoyances of this sort and I am not sure if it has improved since.

I'm using Capture One—I tried darktable (I think they like the "no capital d"), but on MacOS it is a nonstarter, or was when I attempted it.