I run a small team. I have to be able to stay 1 page ahead of every type of developer so I can properly check their work. I get about 5 hours every night. I am usually fine but catch up a bit on the weekends and get the normal 8
7 at best but that's mostly because 2 kids. Note that in the past I couldn't operate without 7-8hrs sleep. Since I have kids, I can work on 6 :)