Yes and Yes
I noticed a drop in fuel consumption too although mine was added at the same time as an HPFP, (wasnt bad tbh couple of mpg) infact for me fuel wise completly standard i averaged 31mpg stage 1 with an intercooler went up to 34mpg and stage 2+ was roughly back at 30-31 mpg so not to bad at all !
Power wise on its own im not sure what youd be getting but combining it with a map probably about 15-20bhp on a GTI, although id say its wise to go for HPFP at ther same time as the OEM pump seems to struggle to keep up in the mid range. Noise wise it is feckin amazing best smile factor mod you can do IMO