I'm not sure what's the argument here... There's more to it than 10BHP... You listed it yourself... 7-speed S Tronic. So it's a fact there's more to it than *just* 10 BHP
and just from a meachnical stand point.
Now if you already own a S3 8V is it worth upgrading? There's no definitive answer to that mate. The reasonable answer would be there's probably not enough in the facelift to make it a compelling upgrade especially if one stands to lose a bunch of money in the process. But say money is not an issue and you like the latest greatest then by all means why not upgrade? (unless you want Sepang Blue that is... Another can of worms!)
VC is a marmite option possibly but most likely this is where the future is headed. You like it you spec it you don't well nobody forces you!
In your case (I assume you have a S3) the FL S3 doesn't seem to offer enough for you to upgrade and therefore you should enjoy your S3
For the rest of us who'll get the new FL S3 we sure will enjoy the extra power, 7-speed S Tronic, Carplay, Android Auto, LEDs, etc...