I've been working 4 days a week, 32 hours, for 4 years and I will never go back. It has made me hesitant to look for other work, I'm not sure if get the same deal, but so far I'm happy where I am.
As others have said the ratios are awesome. I have 15 days off every 20 days instead of 8. For a 20% pay cut, while getting full benefits.