Seamus Condron at PCMag.com is a longtime iPhone user and self-admitted Apple fanboy, but he decided to keep an open mind and test drive a Google Nexus.
It didn’t go well:

On a spec sheet, the Nexus 5’s HD display trumps the iPhone’s considerably. And don’t get me wrong, the Nexus screen is impressive, but I prefer my iPhone 5’s. For one, it seems some of the third-party app icons on the Nexus are degraded, which I venture to guess is the fault of the app makers. That said, the app design of some of my favorites seem considerably less elegant than on iOS 7 and fonts also look bigger than necessary. In the end, I think the uniformity of iOS 7’s interface design strongly influences how I feel about how things look on the screen. I may have come around on that if I had more time with the Nexus 5, but my first impression is usually the last.
Sounds consistent with my experiences using Android—although I know the “stock” Android experience is different than what I experienced on the Samsung Galaxy S3.
My disappointment with Android comes from thousands of tiny cuts.
There’s many little details they either weird or not right: crappy typography, hokey iconography, cheesy clocks to put on your home screen, weird 3-D transitions between home screen panels, blind adherence to the Android flush-top menu bar with apps, the weird back button, choppy UI transitions, clunky icon/text sizing in the status bar, a weird mis-mash of flat & textured/gradiented UI elements.
Using an Android device feels like driving a 2010-ish, base-model Toyota Corolla (or Honda Civic)—it has everything you need in a car, but there’s just no life to it. The interior is drab and generic, the handling is fair, acceleration is weak and everything feels flimsy and plastic.