Hi I know a lot of people often wonder about Buggy Boards and I just wanted to share my experience of the Baby Jogger board with my BJCM in the hope it might help someone!
The board is soooooo easy to fit - it litterally snaps onto the bar and then has some ties to slip through and is just as quick to remove as well.
I use the board on the shortest setting as my DS likes to put his head up and under the handlebar and he really loves the board (he is 4yo).
It easily flips up/down if not in use/when required again.
I do not know if it fits any other pushchairs (I know it definitely doens't fit the nipper 360 as the parts where you attach are wider than the bar than you fit to :() - however if it does physically fit others it would be so easy to swap it.
My experience of the BJCM is that the BJ board works really well with it!