I have the same thoughts.
Explore could navigate you to address/POI, and it has a bigger screen with touch.
However, 530 is smaller, it has a better battery life and the same maps IIRC. Also, it could recalculate route on the fly using their own heatmaps, and it has tonnes and tonnes features which probably I won't use but hey maybe I will, and not all of them require a power meter. It's black also.