Personally I think 14"x21" is the sweet spot for big boards. This one is too big to wash in a normal sink without making a mess of things. Unless you're doing brisket or other big foods I'm not a fan of the jumbo boards.
Discussion
It’s the cleaning process that I am a little bit hung up on. I have 4 chopping boards, 3 of which are the perfect size in relation to the sink and the drying rack to make cleaning a breeze, especially in between different types of prep during the same session. From time to time I could really do with a bigger one though 🧐