I have given up my 1/2 glass of wine a night habit, and I feel better for it!
I literately only used to have 1/2 a glass because I knew it 'didn't agree with me'. For the last 2 weeks since giving it up I have felt happier, less grumpy and lethargic in the morning, more chatty with DH.
It is a subtle shift and I am waiting for the crash but even today when I can know that I haven't had enough sleep I feel less down about the fact.
Just thought I would share my observations.