The work was interesting though and very well suited to my skillset so I asked to work a 30 hour week instead so I could do a little freelancing on the side and make up the difference.
6 months later I haven't started freelancing at all, and I simply enjoy the extra time I have to pursue other interests. The unexpected part though is that I am undeniably more productive than I've ever been while working less actual hours.
I definitely use some of the free time for thinking, but I think I also end up being vastly more efficient when I'm in work mode as well.