The Nexus 4 and even more so the Nexus 5 are really nice devices. I switched from iOS to Andriod and liked the switch. My wife did the switch too and liked it.
Many mid/lower end phones feel completely unusable without a custom ROM.
Then when you get into cloud services (Gmail, Maps, Google Now, etc.) Android has a clear advantage. So depending on what parts of the smartphone experience a user prioritizes, a logical argument can be made for either platform.