Thank you for your input, sound67, and thank you so much for the pictures! I just couldn't stop myself admiring that diagonal framed mahogany board. That shimmer and "lively" character of that surface looks wonderful.
Before deciding to go with walnut I actually was considering that mahogany version also, but after I saw the pictures at rechapados ferrer website they made it look so red that I dismissed it as too glaring. However in your picture the board looks so much more natural and I think I have to think this through again. I have bud rosewood/boxwood pieces so in terms of contrast they should be fine with either one I suppose.
I'm thinking of getting a board with 60mm squares at some point and was contemplating between the two aforementioned manufacturers. Walnut/maple Ferrer board is 77,50 euros incl. postage at niggemann, and Weible is just under 80e total at topschach. So pricewise they are close enough.
If those of you having experience with their boards could tell me if there are any differences qualitywise, or if there are any other reasons to choose one over the other, let me know.