how many hrs of sleep do you get ?

I don't think I've ever gotten a solid eight hours in the past few years bar a massive sleep after trying to get over jet-lag on my way to Tokyo for a holiday. I'm certainly in the 3-6 camp like yourself, I go to bed at around midnight and wake around 6:30, works for me. I think as long as you're not running on one hour a night, you do you in that regard. You know your body in my eyes anyway.