I'm not looking for the absolut truth about this subject, nor looking for a scientific explanation, I just want to hear about your experiences.
So, empirically I know that practicing with traditional media (pencils, acrylics, oils, etc.) helped to improve my digital painting skills a lot. On the other hand, I've been doing a lot of digital-only pieces (generating traditional media textures or basic sketches/layouts at the most) and I see a lot of improvement in that area. Buuut, I feel that my traditional skills are somehow getting poorer, so I plan to go back to the drawing board soon.
I'm just curious, let me know what you think.