I agree that this is something where personal preference plays a big role. However, I prefer physical boards to be on the large side (40 to 50cm). It's not just about board vision, but also being able to easily move pieces. 30cm square is about as small as I would go, and that's ~12".
I play most on computer though, where I find a smaller board makes it easier to get a global view of the board.
I know it's mainly personal preference, but...
I do like smaller play sizes for compactness, for setting up in bed with a study book... (at least I'm assuming I will prefer this).
I like the idea of being able to just pack something up and take out when I want.
I should mention, what I'm looking at is a 9.5" folding/travel magnetic set. Has a wood look (just plastic), King is 5cm tall, and has rank & file numbering.
Only worry is:
(1) is 9.5" just too cramped to get a sense of position and pattern recognition?
I mean, is there any concern going from that to a larger board would mess up positional comfort?
I'm just thinking in the sense of musical instruments, going from one scale size to another, there being a slight adjustment as positions and shapes are a little different.
(2) is it recommended to learn on a larger board, or does it just not make a difference? I ask because I read a review the person said they wasted their money because it was too small to learn.
Or as usual, am I just being ADD and delaying?