GF,
Yes I agree with you. Most people will be better rested going to bed after unwinding with the rest of the crew.
I've gone to bed early in the past because I've got a long day coming up, and just layed there twidling my thumbs. Get rid of the stress and sleep soundly. Good advice!
It is never good to roster (or be rostered) min rest the whole time. However on some occasions that is not always the case, and if a crew have fourteen hours rest it's up to them how they spend it. Long time since I did crewing but i seem to remember something in CAP371 about responsibilty of crew to ensure adequate rest is achieved within the given period.
Maybe as you say, with more sensible rostering crews would nearly always have the chance to relax, unwind and still have enough hours to use up in slumberland. Back to the age old problem of what you have to work with I suppose.