Originally Posted by Rogerbu
As said above - deliberately changing down is also useful when going downhill with a caravan - simple engine braking.
Agreed, most useful for reducing/maintaining lower speed downhill. I also find manual useful on long motorway drives where I can keep in 8th gear but be in sport mode for the better steering feel and control which it gives, whilst maintaining economy. Engaging Sport mode at 80 mph increases revs by 25% from 2000 to 2500 on the 2.0D, so in manual I have the best of both worlds.