1) iPhone - no contest here. The company that pioneered the platform is still the frontrunner.
2) Windows 8 Phone (Lumina 920) - Lack of apps and new OS is what is keeping them from reaching higher rankings.
3) Galaxy S3 - extremely fluid... ALMOST on iPhone level.
4) Nexus 4 - sorry...
To everyone suggesting I reboot... do you really not think that Ive tried that?
Ok, but what happens if I want to use Google Play Music to play music? Am I going to have to compromise being able to listen to music on my phone for battery life?
See title. Something like 60-70% of my battery is being drained by Mediaserver on a regular basis. I charge my N4 overnight, take it off the charger at 8am, by 11am its at 60% life... I had not used the phone at all!