I've been working 32 hour weeks ever since my daughter was born 2 years ago. Mondays are my day off, we go to music classes, walk on the park and just spend time together.
On tuesdays I'm "hungry" when I go back to work. I think this is the perfect balance for me and I feel I'm more productive than ever.
It may not be for everyone, and it's definitely a privilege, but if you can, I really encourage you to try it out.