In reply to Stone Muppet:
Lakes, yeah its great when its not pi$$ing down.
Weight wise, slightly lighter if you don't run UST tyres. You don't really need them. To be honest though the weight isn't the big bonus.
The one downside is that you still need to carry a tube because if you do get a sliced tyre, then you're going to have to put a tube in to get home. The Stans will plug most small holes (thorns etc)so punctures are rare.
The other poster mentioned he's only 10.5 stone (I wish!) which undoubtedly makes a difference as he seems to be able to run a low pressure tube setup. It doesn't work for me.
Back to the tyre debate, I wonder what Danny Hart uses?