Android's biggest weakness is the horrible upgrade situation. Where iOS and Windows Phone users are generally always running the latest version, Android users generally have to settle for whatever version the likes of Samsung and HTC bothered to release for their device. This is a horrible situation for developers and user alike, and, in my view, should be Google's number one priority.
Unless, of course, you're running a custom ROM. This morning my Find 5 greeted me with an update notification, but that's normal - I get a new OmniROM OTA delta update every morning. This time, however, something was different: the version number clearly stated this update would bump my Find 5 from Android 4.4.2 to 4.4.3. As it turns out, the OmniROM team is already pushing 4.4.3 to all the devices it officially supports (52 phones and tablets).
A mere three days after Google pushed 4.4.3 to AOSP.
Thanks to the tireless work of our own Xplodwild, Omni has now merged the changes to Android 4.4.3, and these will be rolling out in nightly builds for the 5th June. As I write this, builds are scheduled to start in around 20 minutes or so, and will appear at our download pages once they are completed. They will also be available through Omni's inbuilt delta OTA updater, as always.
This is just one of the many, many reasons you should be running a custom ROM. Aside form the fact that a proper custom ROM is lighter and cleaner than the crappy OEM ROMs, they are also more secure because they tend to be up-to-date. In addition, warranty is not an issue because, at least in the EU, rooting and custom ROMs do not void your warranty.
As an aside - the fact that a single person, Xplodwild, can make sure Android 4.4.3 runs on 52 devices within a matter of days of the code becoming available is all the proof you need (in case you still needed it) that carriers and OEMs are simply incredibly incompetent at doing their job. Sure, they have to provide warranty and service so some form of delay is understandable because they require more testing, but the way they refuse to update most, if not all, of their devices in a timely manner or even at all should be a crime.