power loss..

I bought my A3 used with a GHL 3in TBE already installed.  I am not a fan of the exhaust note, so I am considering going back to stock.
 
Will I see a significant power loss from doing this?  Anyone have any insight? 
 
(oh yeah, I have Revo stage 2 installed also)
 
Thanks.

I would just switch out the CAT-back part and leave the DP.   That will significantly reduce the exhaust volume but still keep most of the power.   Do you have the Oetty rear valence?   The stock exhaust is a dual pipe on the driver's side and that would look funny with the kit installed.
 
Cheers!