It should come as no surprise given the large number of rumors lately, but Google's just hit the Nexus 5 with the latest version of Android, 4.4.3. If for some reason you're not receiving an OTA notifier yet, it should come soon. For those not patient enough to wait, there are some steps to perform a manual update, but given the slight complexity and the fact that the changelog doesn't introduce anything that important, waiting could be a safer bet.
Nonetheless, despite it not being a major upgrade, 4.4.3 encompasses a staggering 7,454 changes under-the-hood. The biggest ones revolve around a redesigned dialer, and performance boosts for a number of native applications, such as Chrome. It also features a bunch of device-specific bug-fixes that might have plagued you.
New Android 4.4.3 Dialer Is Big And Bold
Like all new Android version releases, it's hard at this point to tell exactly which devices are going to receive the update. We've updated a Nexus 5 at HotHardware just fine to 4.4.3, and a friend of mine in the UK updated his Nexus 7 Gen 2 to it as well. My Nexus 7 Gen 1 isn't able to update at this time, but I'm not sure if that's due to me simply having to wait, or because this will be the first update that model doesn't receive (it's going on two-years-old, after all).
If you're using a Google device and have updated to 4.4.3, let us know in the comments what you think. Also, please mention which device you're using so that we can monitor the rollout!