As you probably know, the DS, 208 and Corsa are all built on the same platform with the same battery system. The 2008 is the second smallish SUV to join the DS3.
I chose the DS3 because of its relatively high seating position and ease of access/exit because of that. Looks wise, I think the 208 has it though I do like the Corsa too. All of the reviews seem to agree that the DS3 has the edge on things like ambience, noise, comfort and ride quality. I’m really happy with my choice. No regrets whatsoever :-).