The 6 hrs of uninterrupted sleep worked well. Although waking up in the middle of the night to respond to an enemy attack, wearing only goggles, boots and underwear, would be kinda cool (just like in the army
), its still better to get some proper sleep and wake up in the morning fresh and ready for battle, as the whole day is ahead of you. And as stated earlier, tired people can be a bit...grumpy, and that might lead to god knows what.
Cougar's proposition sounds pretty cool and might work well for a bit more serious milsim event, or a shorter one, but I'd still prefer the current system for the huge Berget events, as with Cougar's system in the worst case scenario you can spend something like 3 nights without proper sleep (shooting & shouting in the base right next to you, some people waking up and running out from the tents etc), and that may take it's toll afterwards.
The rule that the bases were offgame during the night was a good thing, as those who wanted some action could still fight during the night, but not in the bases. Keep this system indeed, especially if the future games are as long as this one was.