You state the obvious which really isn't saying much... Of course, an operator is going to optimize their settings so their RX is above the noise-floor if possible. Furthermore, if it truly "makes no difference... " then there wouldn't be a REF option on Menu <2> in the first place. I'm always using it and know exactly what it does and fear no aspect of my radio, and that's including the manual. There are times you want to be able to see the weaker signals a bit more clearly, or diminish the footprint of stronger nearby signals without adjusting the RFG once it and other settings are optimally set. It is no different than adjusting the "contrast" button/knob on your old CRT tube screen or using the contrast or brightness feature in your phot0 editing software. It even says as much on pg./section 5-5 of the IC-7300 Full Reference Manual.