^ All RAW converting programs have their pluses & minuses.
Lightroom is the most common program with tons of online tutorials available & it's relatively easy to get very good high ISO images out of it. The downside is the subscription model, especially for those that don't put much use to it.
RawTherapee can hold on to fine detail quite well, but as you start to go high ISO, you'll see that it also holds on to chroma noise a bit more. If you use the aggressive NR settings, then is smears out the color. The amount of settings available can also be overwhelming to the newcomer.
Darktable is supposed to be the Lightroom alternative, but it seems more harder to get good looking high ISO images out of it. The tiny little slider buttons also get on my nerves at times as I try to hold & slide them.
I would love to see someone put up a darktable thread on this forum to share their processing tips & tricks.
The Pentax DCU has hands down the best color available at high ISO, but the fine details will start to get smeared. Not to mention that its very laggy & buggy.
One thing is for sure. They all produce better images that what the out of camera jpeg engine can produce once you learn how to use the program. I'm kind of dead set on RawTherapee. I even
compile my own version on Windows on occasion. I do use DxO & Pentax DCU on occasion, but it's kind of rare. DxO doesn't batch as easily & Pentax DCU is extra laggy on my machines.