I think it depends.I know holding your bitcoins is always profitable as it's price keeps on rising.But there are some situations when we are in the need of money so at that time we cant wait for it's price to rise .So at that time we have to spend our Bitcoin. According to me ,we not earn only to save but also to fullfiil our needs .So according to me the smart way is to save 60-70% of our bitcoins and spend rest of them(30-40%).