Yeah it makes a difference when you get a good combination of online board and pieces. Some bad combinations can make everything look very foggy.
Much to my chagrin I am finding out that I see much more (tactics etc.) on the screen than with real board and pieces on the table. When I play an online game with a nice chess set on the table (my son moves the opposite side) it seems I overlook more than usual. That gives me great pain...

I know this isn't the real physical stuff, but we spend so much time playing and analysing online these days that the online board and pieces we choose are an important consideration. For me, I prefer the look of the "book" pieces, perhaps because they bring back many fond memories of looking at games and positions from books when I was a child (before the internet age). The other choice is the board, and for me I like "walnut", as it looks to me like a natural board you see in major tournaments, or even at the world championship match. To totally nerd out, I prefer the "coordinates" to be outside the board but am toying with the idea of turning them off as I rarely look at them.
Interested to hear what others choose and their reasons why.