Being self-employed at the moment, I'm contracting to pay bills and working on my company, it's the same thing as a never ending crunch time! I certainly feel like I'm getting more done than a 40 hour week, but maybe I'm not getting enough rest to know the difference. :P
The way I solved it was by setting actual work hours and sticking to them. Anything that came in outside work hours could wait until the next day.
I feel like one of the worst parts about a compressed work schedule is that I've mostly stopped playing & exploring, and exploring is where the good stuff happens. Many of my most important personal developments and achievements were on "fun" time, even if it was work. Doing overtime and working too much like I'm doing now mutes that.
I have some commitments in the short term that mean I can't fix this very quickly, but long term I aim to be where you're at for sure.
I definitely recommend it if you can take the salary hit.