I disagree completely, I think Androids memory management sucks, at least up to ICS, JellyBean seems better
Many times I would watch as my ram was sucked to near nothing and using a task killer sorted it
Yes it could be rogue apps but even still, if you don't have a way to manually stop them and Android does nothing to help, you end up having to reboot
JellyBean I haven't needed to use it very much and just leave the widget on the homescreen to show how much ram is available, plus the recent apps button now hsa a "stop all" feature added in the rom I use and that works fine
See, this is the thing. Your RAM SHOULD be used, otherwise it's wasted. Just because your RAM is in use doesn't mean you need more. It means the system is keeping recent apps in memory in case you switch back to them. Once you need that memory, it will close something older that it had open and free it up. This is why it has been repeated again and again that task killers are useless, and it's 100% correct.
That said, Juice Defender is not a task manager and does offer some potential benefits. It allows you to turn on and off features of your phone to save battery. A well tweaked Juice Defender config theoretically could save you some extra battery.
You might be onto something lol.
This is a very definite effect when getting a new phone. Most people will deny this, but I've seen it be true 90% of the time. When you get a new phone, you play with it more. You turn it on to show people, you turn it on to check something, you download all kinds of new apps, etc. This adds up and reduces battery life quite a bit in the first few days of owning a device. There's really no such thing as battery calibration with lithium based batteries, so don't worry about any kind of battery conditioning or completely charging and completely discharging or anything like that. Constantly turning it on and off will make it turn on and off stuff like wifi constantly and keep it out of deep sleep for longer, which will affect battery.
I went back to using my iPhone for a few days and it's highly noticeable how much more battery life I get. My Nexus 4 barely through a day before dying.
See, maybe we're seeing this different, but how long exactly do you need your phone to last? I'm not sure how the battery life is on the N4 in general, but with my One X I get 24 hours pretty easily, but if I were to play a bunch of games or use it heavily, it would be less. I have a charger at work and at home, most of the time I'm no more than a few hours from a charger, so I don't really see the huge deal about battery life as long as you can last around a day.