i did not go for light for 2 main reasons, i am heavy so the grammes i save with ££ are a fraction of what i'd save if i ride my bike more and drink less.. i can at least "ride more" the second option is not likely 😛 .
Secondly i am never going to be little and have a bad habit of breaking things no matter how hard i try not to so i buy bombproof and if its light its as an an afterthought.
So for me its Light, cheap, strong pick two – or just get bombproof. I think the lighter the better but its diminishing returns for your wonga and choice of bike gear depends as much on the riders conformation, riding style/skill and terrain. Bling/tarty bike/bragging rights also have major influences on this topic, its our hobby and our cash so fill ya boots and do what makes you happy. As long as your happy who cares 🙂