A lighter bike does have its advantages and if you can afford it, why not?

Get the Tarmac S-works, much more aggressive frame , lighter, stiffer, better power transfer, and you will notice better acceleration. Requires slightly less effort when varrying speeds, also when climbing which means less fatigue. Everyone here wishes they can have a lighter more expensive bike. A nicer bike will want you to ride it more and eventually get faster and faster. Get it and feel the power of the S-works under you as it propels you past your friends!