Thanks for the 2.6.1.notice, it looks like I need to finally a compile a version myself - running Debian stable (Stretch) with the 2.4.4 backport currently, made reasonably fluent by an AMD RX 480, which I bought just for image processing (opencl).
It's my second attempt on moving from Rawtherapee to Dartable - this time more successfully. I'll likely be running both side-by side for some time longer, with Rawtherapee for more specialized things like pixel shift or for recovering noisy images. Even though i went through some articles and noise handling, I feel more confident with Rawtherapee. I need to put
Noise reduction in Darktable - Tomas Sobek Photography on my reading list for 2.6.
The main features drawing me to Darktable are masks & multiple instances of modules. Here's a recent example, cross-posted from
Fisheye Fever Club -- Flaunt your fisheye photos! - PentaxForums.com. Noise-wise, I used the bi-lateral median filter masked to the sky and non-local means, chroma only. Otherwise, I hope this picture doesn't nearly look as heavily processed as it is:
Using, besides the basic ones, 3x color zones (hue by hue - masked, lightness by saturation, saturation by hue), global tonemap, graduated density (masked), lens correction (manual), vignetting. Even with good hardware support, this gets slow - several seconds on each change for the preview update.