4.4.3 (and 4.4.4) should have better battery life since they fix a couple of wake lock issue:
https://funkyandroid.com/aosp-KOT49H-KTU84L.html4.4.4 is just a fix on a OpenSSL bug
https://funkyandroid.com/aosp-KTU84M-KTU84P.htmli got my nexus 4 last year Jan (although n4 was launched oct/nov 2012). so, it'll be more than 18 months by the time L release next month. minus all the minor iteration, we get free upgrade from the initial 4.2 (another Jellybean) to
- 4.3 (sweeter jellybean) with Bluetooth Smart Ready, OpenGL ES 3.0, merge and re-organize 2d graphics, etc
- 4.4 (kitkat) Project Svelte, experimental ART, new launcher, etc
About the 18 months cycle support, that is just what they officially stated. "little bird" told me the real reason Nexus Galaxy not getting Kitkat is because of it OMAP SOC developed by Texas Instruments; a company that's no longer actively developing smartphone chips.
i m fully confident that L will be released for nexus 4. if goog dont release that, i m jumping ship to iOS.