On screen I can always see the whole board situation without fail whereas on the board, because of my vantage points, I tend to give some bias towards other board positions depending on my posture etc and I take more time as the angle is different which affects my reading. Which is why some people stand up, which doesn’t do me much good either as then not only am I stressed reading out the positions, but I have to do it while standing (extra work).
My friends (who played very few games on screen) told me the exact opposite. I’ve played both on screen and over the board and I’m okay with both. So I suppose it is just a matter of getting used to them.
I think I do better in face-to-face games because they don’t usually have formal time limits and I’m more committed to playing well when I see my opponent face to face. In live-speed online games, I often play too quickly without thinking, especially if the opponent plays quickly.
Definitely screen. But I’ve played dozens of games on a screen, and probably fewer than two dozen games on a board in my life… and probably half of the IRL games were teaching someone else to play.
Stones on the screen are always in a nice regular grid, which I know is not the proper Go aesthetic, but it does feel like it makes the patterns easier for me to see.