It seems like Sprint might be the first U.S. carrier to integrate the new Android 4.4.3 OS update for the Google Nexus 5. If you own such device then you should keep an eye on its Notification panel and be the first to notice the availability of a brand new OS OTA update.
Sprint confirms on their own Support web page that the Google Nexus 5 should get the new software update starting today. The new build number of Android 4.4.3 is listed as 'KTU48F'. The 'KTU' text code is usually used for all the Nexus 5 unlocked US models, which means that all the other models might get the update files later this week, too.
Android 4.4.3 KitKat KTU48F update for Sprint Nexus 5 device will bring support for Sprint Spark on Bands 26 and 41, as well as some improvements to the overall Android OS. This new software is most probably a small one and it shouldn't bring any major changes, it should fix some camera bugs, minor errors, several force closing alerts spotted on a limited number of devices, and other similar small problems that were found in previous KitKat build updates.
Since this new KitKat update will arrive for Sprint Nexus 5 devices, then we can speculate on the fact that all the other Nexus 5 phones should get the new files soon.
You can check yourself for new updates by going to Settings, then About Phone and use the System Updates section to verify for new KitKat builds. Also, make sure to keep an eye here as we will update the post when the first Sprint Nexus 5 user will tip us that the update arrived on his smartphone.
If you do get the update then you should simply click the Download button, then press Install and wait until your Sprint Nexus 5 completes the process automatically.
UPDATE: Two days have passed by and there is no official report on the fact that anyone got this official 4.4.3 Update for their Sprint Nexus 5 device. The Sprint website still states that the update should roll out, but we might have to wait several extra weeks before that happens.
Remember to tell us in comments if you got the new update for your device.