5 hours rest time out of 10 hours duty time. Heaven! 33% out of 10 hours still sounds good in my opinion.
We work 12 hour night shifts, from 7pm until 7am. Usually we get 4 hours of uninterrupted break either between 10pm and 2am, or 2am and 6am. On top of that one or two additional 30min breaks in the evening. Ideally that gives us 5 hours rest time out of 12 hours duty time, making for 40% at the most.