Suppose as the title up there says really, I've read a few about other superbs being remapped (mainly 2L DSGs) but wanted to know if anyone has had this engine done and the outcomes of it?

also an ask about your MPG numbers going up or down regardless of what engine you have, was pondering a "economy" remap but if a stage one remap provides power and mpg I think I could be persuaded to go that way. 

Age old discussion about whether a remap will gain you economy. Short answer is it can of you drive carefully. If you use the extra power at all you will naturally burn through more fuel. A remap will make better use of the fuel but as they pretty much always gain you power this then uses more fuel.