Somehow, according to the HQ article I posted a link to, the RA & HQ work synergistically to augment eachother's best effects. The derms are not sure how or why this happens; they just have evidence that it does. This is good news for those with stubborn resistant pigmented areas. Some people have a sharp pigment demarcation along the side edge of their feet & hands. Blending that line in can be very tough. Some others have very dark knees, elbows & knuckles that are resistant too. This combo, esp if the person tries the occlusive wrap method they recommend, will really lighten them up.
Depending on the person & the extent of it, it can be noticable, yes. In the first few weeks, I peeled like crazy. THe skin became very dry in some areas (so I'd dab on a little olive oil) & after a steamy shower, it would roll off in a gross mass. Creepy, but good to know it was no longer clinging to my face making it harder for the HQ to penetrate.