I feel like more than anything, this example demonstrates the value of lightweight lambdas.

    var totals = splat(get('total'))(orders);

is definitely nicer than

    var totals = orders.map(function(o){return o.total;});

But there really is not much difference between the coffeescript versions (actually, I'd argue the 'map' version is much clearer in intent):

    totals = splat(get('total'))(orders);

    totals = orders.map (o)->o.total