I just got my bronzers in and upon initial swatches, they are gorgeous. Definitely not necessary to own both... I mean, I'm going to keep both because I'm a hoarder like that but they arent vastly different, especially in terms of depth. The Suns already going down so I couldn't take great pictures. I plan on taking better pictures for my blog tomorrow. Upon initial swatching, luminous pulls more yellow and radiant pulls a little more red/orange on my skin.... But it's subtle once applied.
Looking at the screen: left is radiant, right is luminous.