I am fairly vain when it comes to electronics and their looks.
I have owned an iPhone 4, iPhone 5, GN2, and Nexus 5 in the smart phone realm. Other than the small screen size I loved the industrial design of the iPhone 4. Did not like the iPhone 5 near as much and pretty much hated the GN2.
With that said, I love the look and feel of the Nexus 5. It feels solid while also being relatively compact. I also liked that the corners were not "Samsung Round". The corners were sharper.
I know we can only see the back of this phone, but the roundness of those corners is hideous to me. I will wait to see the final product before I make a real judgement, but so far it does looks as round as a Shamu to me.