Looking good Slawomir. The pink HII regions are starting to show. This is not an easy galaxy to process. You've done very well given the small data set.
The blue stars/clusters in the spiral arms are razor sharp and extremely detailed. If I stretch your image a tad, I can also make out the dwarf companion galaxy at about 5 o'clock from the main one. Well done.
I wonder if the core is a little burned out toward blue-white, so you're losing some of the yellow-orange colour, and also losing contrast in the dust lanes close to the central bulge. It's a valid interpretation exactly as it is, of course.
I also got a feeling the image is generally a bit blue-shifted. I am a narrowband guy and RGB is uncharted territory to me. I was also hoping to get more Luminance data but weather was not cooperative at the time.
Honestly, it is a relatively unexciting image of M81 but I had fun putting it together, instead of watching intelligence-dulling TV.
