One of Android's biggest downsides is the speed at which you receive updates: some phones will take months to get the latest version of Android. Ars Technica runs down the best (and worst) manufacturers for quick updates.
This isn't the first time someone's rated manufacturers, but things do change over time, so it's nice to have an up-to-date look. As you'd expect, the Nexus 4 and Moto X were quickest to get the update, while Samsung Devices tended to be slower, likely due to the heavily customised UI.
Of course, some would argue these updates don't matter as much as they once did -- and you're also the mercy of carrier update processes as well. Still, it's a small factor to consider when buying your next phone.